CN114113296A

CN114113296A - Magnetic signal acquisition device, magnetic sensitive immunity detection device and detection method

Info

Publication number: CN114113296A
Application number: CN202210091551.8A
Authority: CN
Inventors: 白石; 崔豪; 侯福旭; 郭大可; 史力伏; 李天舒; 王月; 马雨婷
Original assignee: Liaoning Jiayin Medical Technology Co ltd
Current assignee: Liaoning Jiayin Medical Technology Co ltd
Priority date: 2021-10-12
Filing date: 2022-01-26
Publication date: 2022-03-01
Anticipated expiration: 2042-01-26
Also published as: CN114113296B

Abstract

A magnetic signal acquisition device, a magnetic sensitive immunity detection device and a detection method belong to the technical field of medical detection devices and solve the problems of long detection time, large sampling amount, low detection precision, small detection range, poor anti-interference capability and high application cost in the existing biological immunity index detection technology. The device comprises an excitation winding coil and a detection body, wherein the detection body comprises a detection winding coil and a detection hole on a sample bearing seat, and the detection winding coil corresponds to the detection hole; the detection body is positioned in a uniform magnetic field generated by the excitation winding coil, and the uniform magnetic field generated by the excitation winding coil is vertical to the central axis of the detection winding coil. The whole blood sample analyzer is reasonable in design and compact in structure, can reduce the influence of noise such as a geomagnetic field and an excitation magnetic field on a detection signal, does not need cleaning, separating, airing and other processes, can be used for quickly detecting a very small amount of whole blood samples, and is high in detection sensitivity and wide in detection range.

Description

Magnetic signal acquisition device, magnetic sensitive immunity detection device and detection method

Technical Field

The invention belongs to the technical field of medical detection devices, and particularly relates to a magnetic signal acquisition device, a magnetic sensitive immunodetection device and a detection method.

Background

Immunoassay is a method for detecting body fluid components based on antigen-antibody specific binding, is the largest branch of the market in the field of in vitro diagnosis, is widely applied to detection of tumor markers, cardiac markers, infectious disease antibodies and the like, and has important scientific and industrial values. The traditional immunoassay technology comprises enzyme-linked immunosorbent assay, electrochemiluminescence, radioimmunoassay, fluorescence immunoassay and the like, but the method generally needs to carry out detection under a solid phase, so that the precision is lower and the linear range is smaller, or needs to use a serum or plasma sample obtained by separating whole blood under a semi-liquid phase, and separate an unbound free reagent after the reagent is fully bound with a detected object so as to obtain the accurate content of the detected object. At present, the applications of magnetic particles in immunoassay are mainly divided into two major categories, including immunoadsorption or magnetic separation using antibody-activated magnetic beads, and a magnetic-sensitive immunoassay analyzer using magnetic particles as labels. However, the immunoadsorption and magnetic separation are only to filter the corresponding components in blood or other types of samples, and are not directly used for detection indexes; the existing magnetic-sensing immunoassay analyzer is only a non-separation-free semi-liquid phase detection mode, namely a reagent separation and cleaning process is still not combined, a solid phase substrate is still used in a reaction process, full-liquid phase separation-free detection cannot be realized, the detection time is long, the detection range is narrow, and the magnetic-sensing immunoassay analyzer is difficult to be suitable for the detection condition requiring high-sensitivity and on-site rapid quantitative diagnosis.

In recent years, a separation-free liquid-phase magnetic-sensitive immunoassay technology is of great interest internationally, and the characteristic that the superparamagnetism of magnetic nanoparticles is influenced by the change of relaxation time under the liquid-phase condition is utilized to specially design a particle superparamagnetism core and each functional coating layer, so that the superparamagnetism of the magnetic nanoparticles is obviously changed after the magnetic nanoparticles are combined with detected components, and the rapid quantitative analysis of the combination reagent and the free reagent in a mixed state is innovatively realized. The method not only realizes the full liquid phase detection of various detected indexes, greatly accelerates the reagent reaction and detection speed, but also has extremely high linear range and sensitivity by virtue of the progress of the high-performance weak magnetic sensing technology, supports the detection of whole blood, serum, plasma and various tissue fluid samples, and has important significance for on-site high-sensitivity medical diagnosis.

The existing separation-free liquid-phase magnetic-sensitive immunoassay technology is mainly realized by two methods, namely magnetic signal detection on the magnetization attenuation amount of a binding label under alternating current excitation and magnetic signal detection on the increase change of the relaxation time of the binding label under direct current excitation. For the direct current detection method, a GMR sensor, a TMR sensor, and a superconducting quantum interferometer are generally used to detect the marker signal; however, because the direct current detection signal is easily affected by the external magnetic field, the detection signal sensitivity is not high only by using the common magnetic shielding layer, and the high-performance large magnetic shielding device (such as a multilayer permalloy or a superconducting diamagnetic shielding layer) is high in price and difficult to move, thereby greatly limiting the application scene. For the alternating current detection method, the prior art generally adopts an excitation coil to generate an alternating current magnetic field, and uses a detection coil as a signal receiving device to measure the alternating current magnetization signal of a detection reagent, although a high-performance magnetic shielding layer is not needed, the detection result is very easily influenced by the excitation magnetic field and noise such as external electromagnetic interference, the detection sensitivity is equivalent to the GMR type direct current detection effect under the common magnetic shielding layer, the index effect of high-sensitivity measurement on the troponin and the like is not good enough, and therefore, the signal intensity and the noise suppression method of the detection reagent need to be improved so as to realize the ultra-fast large-range full-liquid-phase magnetic-sensitive immunodiagnosis with extremely high signal-to-noise ratio.

Disclosure of Invention

The invention aims at the problems, and provides a magnetic signal acquisition device, a magnetic sensitive immunoassay device and a detection method, which are used for weak magnetic signal detection of biological immunity indexes, can reduce the influence of an excitation magnetic field and environmental noise on detection signals, can quickly detect a very small amount of whole blood, serum, plasma and various tissue fluid samples without the processes of reagent cleaning, separation, airing and the like, and have the advantages of high detection sensitivity, wide detection range and strong practicability.

The technical scheme adopted by the invention is as follows: the magnetic signal acquisition device comprises an excitation winding coil and a detection body, wherein the detection body comprises a detection winding coil and a detection hole in a sample bearing seat, and the detection winding coil corresponds to the detection hole. "corresponding" means that the detection hole may be disposed outside the detection winding coil or may be disposed inside the detection winding coil. When the detection hole is positioned at the outer side of the detection winding coil, the direction of a magnetic signal (magnetic induction line direction) generated after the detected sample in the detection hole is excited by the excitation winding coil is distributed along the direction of an excitation field; simultaneously, when the detection sample is placed in the middle position outside the detection winding coil, is close to the detection winding coil as far as possible, the magnetic signal (magnetic induction line) that can make the sample excitation produce passes the upper and lower two parts that detect the winding coil to the at utmost, and detects the magnetic signal that the direction is opposite that winding coil upper and lower two parts received, can form syntropy electric current in detecting the winding coil because of the differential formula structure of coil, promptly: the value of the detected magnetic signal is the sum of the absolute values of the signals detected by the upper and lower detection coils. However, when the detection hole is positioned on the inner side of the detection winding coil, the detected sample signal is weak; and, when the detection sample is placed at the middle position inside the detection winding coil, since the magnetic signal generated after the sample is excited is the same as the excitation field direction (horizontal to each other), most of the magnetic signal generated by the sample being excited does not pass through the detection winding coil, that is: the detection winding coil does not detect the magnetic signal of the sample. The detection body is positioned in a uniform magnetic field generated by the excitation winding coil, and the uniform magnetic field generated by the excitation winding coil is vertical to the central axis of the detection winding coil.

Preferably, the detection winding coil is wound on the detection coil winding framework, excitation coil winding frameworks are symmetrically arranged on two sides of the sample bearing seat, and excitation winding coils formed by Helmholtz coils are arranged on the excitation coil winding frameworks on the two sides.

Preferably, the detection winding coil adopts a differential winding structure; the detection winding coil is composed of a detection coil forward winding section and a detection coil reverse winding section which are separated from each other and are continuously arranged along the axial direction of the detection coil winding framework, and the winding number, the winding length and the winding layer number of the detection coil forward winding section and the detection coil reverse winding section are the same.

Preferably, the sample carrier is rotatable relative to the excitation winding coil. The angle position between a connecting line between the sample in the detection hole and the center of the projection of the detection winding coil in the horizontal plane and the uniform magnetic field line generated by the excitation winding coil is changed by adjusting the position of the sample bearing seat.

Preferably, the detection coil winding framework comprises a detection framework main body, the detection framework main body is respectively provided with a detection coil forward winding groove and a detection coil reverse winding groove, and the detection coil forward winding groove and the detection coil reverse winding groove are sequentially arranged along the axis of the detection framework main body; the size of the detection coil forward winding groove is the same as that of the detection coil reverse winding groove, and the detection coil winding columns with the same outer diameter are arranged in the middle of the detection coil forward winding groove and the middle of the detection coil reverse winding groove; meanwhile, a winding groove isolation section is arranged between the detection coil forward winding groove and the detection coil reverse winding groove. Winding a detection coil forward winding section of a detection winding coil on a detection coil winding column in the middle of a detection coil forward winding groove of a detection framework main body, and continuously winding a detection coil reverse winding section connected with the detection coil forward winding section on the detection coil winding column in the middle of the detection coil reverse winding groove of the detection framework main body; therefore, the detection winding coil with a differential structure formed by the same winding wire is used for detecting weak magnetic signals, and the influence of the earth magnetic field and the excitation magnetic field on the detection signals is reduced.

Preferably, the detecting coil winding framework and the sample bearing seat can adjust the axial relative position. The vertical relative position between the detection coil winding framework and the sample on the sample bearing seat outside the detection coil winding framework is changed through adjustment, and then the noise influence caused by the change of the test environment is offset by utilizing the adjustment of the position in the vertical direction.

Preferably, the sample bears the seat including bearing the seat main part, and the middle part that bears the seat main part is provided with the detection coil mounting groove, the inspection hole sets up in detection coil mounting groove upper end open-ended periphery. According to specific use requirements, the detection coil mounting groove can be arranged in the middle of the upper end of the bearing seat body, and also can extend from the middle of the upper end to the inside of the bearing seat body, and the detection coil mounting groove can also penetrate through the middle shaft of the bearing seat body. A base is arranged below the bearing seat main body, and a supporting connecting block is arranged between the base and the bearing seat main body; in order to bear the split type setting of seat main part and in the seat joint inslot that bears of supporting connection block upper end middle part to the detection coil winding skeleton and sample are placed respectively in the detection coil mounting groove and the detecting hole that bear the seat main part. In order to realize the adjustment of the axial relative position between the detection coil winding framework and the bearing seat main body, the detection coil winding framework is positioned in the detection coil placing groove, and a detection framework connecting hole is formed in the middle of the detection coil winding framework; the detection framework connecting hole is connected with a detection framework positioning rod vertically arranged in the detection coil mounting groove through threads. Namely: an adjusting structure for adjusting the axial relative position is arranged between the detection coil winding framework and the bearing seat main body, the adjusting structure comprises a detection framework connecting hole arranged in the middle of the detection framework main body of the detection coil winding framework, and an internal thread is arranged on the inner wall of the detection framework connecting hole; the detection framework connecting hole is connected with an external thread of a detection framework positioning rod arranged in the detection coil mounting groove through an internal thread. The lower end of the detection framework positioning rod is connected with a supporting connecting block on the base; the detection coil winding framework is positioned and placed in the detection coil placing groove of the bearing seat main body conveniently through the detection framework positioning rod arranged in the middle of the bearing seat main body; and the precise thread structure which is matched and connected between the detection coil winding framework and the detection framework positioning rod is utilized to finely adjust the relative position of the sample and the detection winding coil, thereby achieving the purpose of reducing noise and leading the detection of the biomarker to be close to an ideal state.

Preferably, another mode for realizing the axial relative position adjustment between the detection coil winding framework and the sample bearing seat is as follows: the sample bearing seat comprises a bearing seat main body, a detection coil placing groove is arranged in the middle of the bearing seat main body, and the detection holes are formed in the periphery of an opening in the upper end of the detection coil placing groove; the detection coil winding framework is positioned in the detection coil mounting groove and is connected with the bearing seat main body through threads. Namely: according to specific use requirements, the adjusting structure for adjusting the axial relative position between the detection coil winding framework and the bearing seat main body can also be formed by external threads arranged on the outer wall of the detection coil winding framework, and correspondingly, internal threads matched with the external threads are arranged on the inner wall of the detection coil mounting groove in the middle of the bearing seat main body; so that the winding framework of the detection coil in the arrangement groove of the detection coil is connected with the bearing seat body through threads, and the relative position of the sample and the detection winding coil is finely adjusted by utilizing the precise thread structure which is matched and connected between the winding framework of the detection coil and the bearing seat body.

Therefore, the center of a magnetic field generated by exciting a sample on the sample bearing seat is positioned in the middle between the forward winding section and the reverse winding section of the detection coil of the differential detection winding coil through adjusting the axial relative position between the detection coil winding framework and the sample bearing seat. In the process that a sample is placed in a detection hole of a sample bearing seat for detection, the sample is positioned in the middle between a forward winding section and a reverse winding section of a detection coil of a differential detection winding coil, so that a magnetic induction line generated after the sample is excited can be ensured to penetrate through the differential detection winding coil to the maximum extent, and the maximum signal value of the detected sample can be detected under the condition that an external excitation signal is the same.

Preferably, the detection wells comprise at least two wells of different depths. The detection coil mounting groove is provided with a plurality of detection holes along the same circumference, and the detection holes are arranged on the periphery of the opening at the upper end of the detection coil mounting groove; meanwhile, the plurality of detection holes arranged along the same circumference comprise at least two holes with different depths. The detection sample placed in the detection hole is close to the differential detection winding coil arranged on the detection coil winding framework in the detection coil placing groove as much as possible, so that the detection of a sample magnetic signal is facilitated; and according to the specific amount of the reagent in the sample and the detection requirement, the sample is placed in the detection holes with different depths, so that the vertical position of the sample in the detection hole is flexibly changed, and the accurate detection of the sample is facilitated.

Preferably, the side part of the winding groove isolation section wound on the framework by the detection coil is provided with a wiring notch axially arranged along the winding column of the detection coil; the outer end of the wiring opening is arranged at the outer edge of the detection framework main body, and the inner end of the wiring opening is radially arranged at the bottom of the forward winding groove and the reverse winding groove of the detection coil and the outer wall of the winding column of the detection coil. The detection of the entering and exiting of the winding coil in the forward winding groove and the reverse winding groove of the detection coil is facilitated through the wiring gap, the consistency of the winding number of the forward winding section and the reverse winding section of the detection coil is ensured, and the occurrence of fine turn error is effectively avoided; and the detection of the winding layer by layer of the winding coil is facilitated, the length of the winding in the radial direction is reduced, and the interference is reduced.

Preferably, the excitation coil winding framework comprises an excitation framework main body, an excitation coil winding groove is formed in the excitation framework main body, an excitation coil winding column is arranged in the middle of the excitation coil winding groove, and the excitation winding coil is wound on the excitation coil winding column in the middle of the excitation coil winding groove; the lower end of the excitation framework main body is provided with an excitation framework base. Two sections of excitation winding coils formed by Helmholtz coil structures are continuously wound on an excitation coil winding column in the middle of an excitation coil winding groove of two groups of symmetrically arranged excitation coil winding frameworks, and the winding directions, the winding turns, the winding lengths and the winding layer numbers of the two sections of excitation winding coils are the same, so that an excitation magnetic field required for detection is formed, and a sample on a sample bearing seat in the middle and a detection winding coil on the detection coil winding framework are both positioned in a uniform strong excitation magnetic field generated by the excitation winding coils.

Preferably, the excitation framework main body of the excitation coil winding framework is of an annular structure, and an expansion heat dissipation ring hole arranged along the central axis direction of the excitation winding coil is formed in the middle of the excitation framework main body of the annular structure. The expanding heat dissipation ring hole arranged in the middle of the excitation coil winding framework in the annular structure is used for facilitating the placement operation of the detection coil winding framework and the sample, and enough heat dissipation and heat insulation space is formed between the excitation winding coil and the detection winding coil.

And wiring grooves for enabling the winding wires of the exciting winding coils to enter and exit the exciting winding grooves are formed in the left end and the right end of the exciting framework main body respectively. The wiring grooves arranged at the two ends of the exciting coil winding groove are utilized to facilitate the in and out of the windings of the two sections of exciting winding coils.

The magnetic signal acquisition device also comprises a sample matched with the detection hole, the sample comprises a biological functionalized magnetic ball, an antibody buffer solution and a solution of a detected object, the biological functionalized magnetic ball comprises a magnetic core and a hydrophilic coating layer, and a detection antibody which can be specifically combined with the detected object is coupled on the hydrophilic coating layer of the biological functionalized magnetic ball by a biochemical means. During detection, the microscopic form and size of the magnetic sphere are changed due to the combination of the antigen and the antibody, so that the relaxation time of the magnetic sphere is changed, and the alternating current magnetization response of the magnetic sphere is further influenced. The magnetic signal variation is captured by a magnetic signal acquisition device, so that quantitative detection of trace components in blood is realized; and can detect the components in whole blood, plasma, serum and cell disruption liquid in a liquid phase.

Preferably, the detection winding coil and/or the excitation winding coil are made of multiple stranded wires. So as to effectively avoid the phenomenon that the equivalent direct current resistance of the coil is increased caused by high-frequency eddy current.

Preferably, an electromagnetic shield is disposed outside the excitation winding coil. The influence on the detection signal caused by the change of the ambient temperature or the viscosity of the solution and the like is further reduced, the external electromagnetic interference is reduced, the signal to noise ratio is improved, and the detection sensitivity is improved.

A magnetic sensitive immunity detection device comprises the magnetic signal acquisition device and a signal generator, wherein a reference frequency output end of the signal generator is electrically connected with a reference frequency input end of a phase-locked amplifier for locking frequency, and an excitation signal output end of the signal generator is electrically connected with an excitation signal input end of an excitation power amplifier, or a signal source is directly provided by the interior of the excitation power amplifier without adopting the signal generator; and the excitation signal output end of the excitation power amplifier is electrically connected with an excitation winding coil arranged on an excitation coil winding framework to generate an alternating magnetic field, and then the detection coil is excited to wind a sample in a detection hole in the middle of the upper end of the framework to generate a detected magnetic signal. The detection winding coil is electrically connected with the signal input end of the phase-locked amplifier, and the signal output end of the phase-locked amplifier is electrically connected with the signal input end of the processor. Magnetic signals generated by exciting a sample are detected by winding a detection winding coil arranged on a framework by a detection coil, and detected electric signals are transmitted to a phase-locked amplifier connected with the detection winding coil and then transmitted to a processor such as a computer or a cloud terminal for processing by the phase-locked amplifier.

Preferably, an excitation series resonance for reducing ac impedance is provided between the excitation signal output terminal of the excitation power amplifier and the connection terminal of the excitation winding coil. The alternating current impedance of the exciting circuit is reduced by utilizing the exciting series resonance formed by the capacitor, so that the exciting circuit can realize the improvement of the current intensity on the premise of high frequency. The excitation frequency is determined by the relaxation time of the superparamagnetic nanoparticles, i.e. for superparamagnetic particles which are not bound to the detected object, it is satisfied that the excitation period is much smaller than the denier relaxation time of the superparamagnetic particles and slightly larger than or equal to their brownian relaxation time. Generally, magnetic nuclei above 20nm can meet the Neille relaxation time requirements, while Brownian relaxation times are generally availableτ _B = πηd _H ³/2k _B TIs shown in whichηIn order to obtain the viscosity of the solution,k _B Tin order to be a thermal energy,d _His the magnetic particle hydraulic diameter.

The detection winding coil is used for detecting alternating current magnetization signals generated by the magnetic particles, and because the superparamagnetic particles have nonlinear magnetization property, in order to reduce excitation noise interference, a harmonic signal detection method is adopted to detect the signals. The magnetic sensitive immunity detection device can detect magnetic particle signals in an odd harmonic mode or an even harmonic mode. When the excitation field is a pure alternating current field, i.e. only alternating current excitation current is passed through the excitation winding coilI _acThen, the superparamagnetic particles will generate odd harmonic signals; when the excitation field is an AC/DC coupling field, that is, an AC excitation current and a DC excitation current are simultaneously introduced into the excitation coilI _dcThen, odd and even harmonic signals will be generated simultaneously; preferably, the use of the intensity ratio of the multiple harmonic signal can further reduce the influence of the ambient temperature, the change in the solution viscosity, or the like on the detection signal, and improve the detection sensitivity.

Preferably, a detection parallel resonance for filtering and improving the signal-to-noise ratio is arranged between the connecting end of the detection winding coil and the detection signal input end of the phase-locked amplifier. The use of detecting parallel resonance can greatly enhance the detection signal strength and inhibit non-detectionPassing of signal frequency noise; quality factor available for signal-to-noise enhancementQ = ωL/RIs shown in whichωIn order to detect the angular frequency of the antenna,Lin order to detect the coil inductance,Rthe equivalent direct current resistance of the detection coil is obtained. Therefore, to obtain largerQThe excitation and detection signal frequencies need to be increased. However, as mentioned before, the excitation and detection signal frequencies are determined by the relaxation times of the superparamagnetic nanoparticles. In the traditional alternating current detection, magnetic particles have larger hydraulic diameter, for example, the Brownian relaxation time of the magnetic particles with the particle size of 250nm in pure water solution is about 5.9ms at room temperature, the excitation frequency of the magnetic particles is lower than 169.5Hz, the third harmonic frequency is lower than 508.5Hz, and the resonance detection is carried out at the frequencyQValues often only slightly above 1, the parallel resonance does not have the effect of enhancing the signal-to-noise ratio. For better signal-to-noise ratio, superparamagnetic particles with smaller hydrodynamic diameter are optimally used, for example, the brownian relaxation time of magnetic particles with the particle diameter of 90nm is about 0.27ms, the excitation frequency is 3,704Hz, the third harmonic frequency is 11,112Hz, and at this frequency, the quality factor of more than 10 times can be easily obtained. The detection winding coil and/or the excitation winding coil manufactured by using the multi-stranded wires can effectively avoid the phenomenon that the equivalent direct current resistance of the coil is increased due to high-frequency eddy current, and the quality factor of more than 30 times can be obtained under the condition. It will be appreciated that the excitation series resonance provided between the excitation power amplifier and the excitation winding coil, and the detection parallel resonance provided between the detection winding coil and the lock-in amplifier, may be arranged separately or simultaneously, depending on the particular application.

A detection method using the magnetic sensitive immunity detection device comprises the following steps:

step one, placing a sample in a detection hole;

adjusting the output waveform, frequency, voltage and current of the signal generator to control the excitation signal output by the excitation power amplifier;

thirdly, transmitting the excitation electric signal output by the excitation power amplifier to an excitation winding coil, enabling the excitation winding coil to generate an alternating magnetic field in the range of the sample, and enabling the excited sample to generate a magnetic signal matched with the excitation signal of the excitation winding coil;

collecting magnetic signals generated by exciting a sample by using a detection winding coil, and converting the magnetic signals into electric signals;

fifthly, the detection winding coil transmits the acquired signal to a phase-locked amplifier, and then the phase-locked amplifier transmits the digital signal to a processor for data calculation processing and storage; finally, the processed digital signal is displayed in the form of "concentration value of specific minor constituent in blood".

Preferably, in the first step, after the sample is placed in the detection hole, each detection device is started, and background noise is adjusted in advance; the vertical relative position between the detection winding coil and the sample on the sample bearing seat is changed, and meanwhile, the reading of the phase-locked amplifier is observed, so that the background noise is reduced to the minimum.

Preferably, in the first step, after the sample is placed in the detection hole, the position of the sample bearing seat is adjusted in a rotating manner, so that a connecting line between the sample in the detection hole and the center of the projection of the detection winding coil in the horizontal plane is parallel to a uniform magnetic field line generated by the excitation winding coil.

The invention has the beneficial effects that: the invention adopts the structure that the detection coil winding framework is arranged in the sample bearing seat, the differential detection winding coil arranged on the detection coil winding framework is composed of a detection coil forward winding section and a detection coil reverse winding section which are mutually separated and vertically and continuously arranged, and the winding number, the winding length and the winding layer number of the detection coil forward winding section and the detection coil reverse winding section are the same; a sample is arranged on the sample bearing seat and positioned outside the detection winding coil; two symmetrically arranged groups of excitation coil winding frameworks are respectively arranged on two sides of the sample bearing seat, and two sections of excitation winding coils which are continuously arranged along the transverse direction and are formed by Helmholtz coil structures are arranged on the two groups of excitation coil winding frameworks; the uniform strong magnetic field generated by the exciting winding coil is perpendicular to the middle axis of the detecting winding coil in space, and the sample and the detecting winding coil are both in the uniform strong magnetic field generated by the exciting winding coil, so that the detecting winding coil is reasonable in design and compact in structure, the detecting winding coil with a differential structure formed by the same metal winding is used for detecting weak magnetic signals, and the influence of an environmental magnetic field and the exciting magnetic field on the detecting signals is reduced. In addition, the invention detects the harmonic signals of the superparamagnetic particles with nonlinear magnetization property, and further reduces the influence of environment temperature or solution viscosity change and the like on the detection signals by matching with the use of the resonant circuit and the electromagnetic shielding cover, thereby reducing external electromagnetic interference, improving the signal-to-noise ratio and improving the detection sensitivity.

Compared with the immunodetection realized by the existing electrochemical luminescence method, the fluorescence labeling method and the like, the magnetic signal acquisition device has the advantages that the detection speed of the immunodetection is high, the rapid detection of various liquid-phase detection samples can be realized within 5 minutes only by consuming the antigen-antibody combination time without the processes of cleaning, separating, airing and the like, the detection sensitivity is high, the detection range is wide, the practicability is strong, and the high-sensitivity and wide-range detection of 0.1 ng/ml-200000 ng/ml can be realized in the detection of C-reactive protein (CRP); and the sample amount required to be collected is very small during detection, and only 10 ul-20 ul of fingertip blood is required to complete the detection.

Drawings

Fig. 1 is a schematic structural diagram of a magnetic signal acquisition device of the present invention.

Fig. 2 is a schematic view of a structure of the support connector block of fig. 1.

FIG. 3 is a schematic view of a structure of a holder body of the sample holder of FIG. 1.

Fig. 4 is a sectional view of an internal structure of fig. 3.

Fig. 5 is a schematic view of a structure in which the detection coil of fig. 1 is wound around a bobbin.

Fig. 6 is a sectional view of an internal structure of fig. 5.

Fig. 7 is a sectional view of a connection structure of the detection coil bobbin and the carrier body in fig. 5.

Fig. 8 is a schematic diagram of a structure of the excitation coil winding bobbin of fig. 1.

Fig. 9 is a sectional view of an internal structure of fig. 8.

Fig. 10 is a sectional view of an internal structure of fig. 1.

Fig. 11 is a top view of fig. 1.

FIG. 12 is a schematic view of one embodiment of the magnetic-sensing immunoassay device of the present invention.

Fig. 13 is a block diagram of the circuit connections of fig. 12.

FIG. 14 is a flow chart of the operation of the detection method of the present invention.

The sequence numbers in the figures illustrate: 1 base, 2 support connecting block, 3 sample bearing seat, 4 sample, 5 detection coil winding framework, 6 detection winding coil, 7 detection framework positioning rod, 8 excitation coil winding framework, 9 excitation winding coil, 10 bearing seat clamping groove, 11 excitation framework connecting hole, 12 bearing seat body, 13 detection coil mounting groove, 14 detection hole, 15 detection framework body, 16 detection coil forward winding groove, 17 detection coil reverse winding groove, 18 winding groove isolation section, 19 detection coil winding column, 20 detection framework connecting hole, 21 wiring gap, 22 lead inlet and outlet, 23 detection coil forward winding section, 24 detection coil reverse winding section, 25 excitation framework body, 26 excitation coil winding groove, 27 excitation coil winding column, 28 expansion radiating ring hole, 29 excitation framework base, 30 support block connecting hole, 31 detection coil middle shaft, 32 excitation coil middle shaft, 33 signal generator, 34 lock-in amplifier, 35 drive power amplifier, 36 drive series resonance, 37 detect parallel resonance, 38 wiring the tank.

Detailed Description

The specific structure of the present invention will be described in detail with reference to FIGS. 1 to 14. The magnetic signal acquisition device comprises a base 1, wherein a supporting connecting block 2 is arranged on the base 1, and a sample bearing seat 3 is arranged in the middle of the upper end of the supporting connecting block 2. The sample bearing seat 3 comprises a bearing seat body 12, a detection coil mounting groove 13 is arranged in the middle of the bearing seat body 12, and a detection hole 14 (shown in fig. 3 and 4) is arranged on the upper side of the bearing seat body 12 and on the periphery of an upper end opening of the detection coil mounting groove 13; according to the specific use requirement, the detection coil mounting groove 13 may be disposed in the middle of the upper end of the bearing seat body 12, or may extend from the middle of the upper end to the inside of the bearing seat body 12, and the detection coil mounting groove 13 may also be disposed in the middle axis position of the bearing seat body 12. And then bear the split type setting of seat 3 in the seat joint groove 10 that bears of support connecting block 2 upper end middle part with the sample to placing detection coil winding skeleton 5 and sample 4 in the detection coil mounting groove 13 and the inspection hole 14 that the sample bore seat 3 respectively. The detection well 14 comprises at least two wells of different depths. The detection holes 14 can be multiple according to the combined use requirement, and the detection holes 14 are arranged on the periphery of the opening at the upper end of the detection coil mounting groove 13 along the same circumference; meanwhile, the detection holes arranged along the same circumference comprise at least two holes with different depths. In addition, the hole depths of the detection holes 14 arranged along the same circumference may be different. So that the detection sample 4 placed in the detection hole 14 is close to the differential detection winding coil 6 arranged on the detection coil winding framework 5 in the detection coil placing groove 13 as much as possible, and the detection of a sample magnetic signal is facilitated; and according to the specific amount of the reagent in the sample 4 and the detection requirement, the sample 4 is placed in the detection holes 14 with different depths, so that the vertical position of the sample 4 in the detection hole 14 is flexibly changed, and the accurate detection of the sample 4 is facilitated.

The detection winding coil 6 corresponds to the detection hole 14, and the "corresponding" means that the detection hole 14 can be arranged at the outer side of the detection winding coil 6 or at the inner side of the detection winding coil 6. It will be appreciated that the detection apertures 14 may be disposed on the sample carrier 3 outside the detection winding coil 6 or on the detection coil winding bobbin 5 inside the detection winding coil 6, depending on the particular application. When the detection hole 14 is positioned at the outer side of the detection winding coil 6, the direction of a magnetic signal (magnetic induction line direction) generated after the detected sample in the detection hole 14 is excited by the excitation winding coil 9 is distributed along the direction of an excitation field; simultaneously, when the detection sample is placed in the middle position outside the detection winding coil 6, when being close to the detection winding coil as far as possible, the magnetic signal (magnetic induction line) that can make the sample excitation produce passes the upper and lower two parts that detect the winding coil to the at utmost, and detects the magnetic signal that the opposite direction was received in upper and lower two parts of winding coil, can form syntropy electric current in detecting the winding coil because of the differential formula structure of coil, promptly: the value of the detected magnetic signal is the sum of the absolute values of the signals detected by the upper and lower detection coils. However, when the detection hole 14 is located inside the detection winding coil 6, the detected sample signal is relatively weak; also, when the detection sample is placed at the middle position inside the detection winding coil 6, since the magnetic signal generated after the sample is excited is the same as the excitation field direction (horizontal to each other), most of the magnetic signal generated by the sample being excited does not pass through the detection winding coil 6, that is: in this particular inner position the detection winding coil 6 cannot detect the magnetic signal of the sample.

In the detection coil mounting groove 13 in the middle of the sample bearing seat 3, a detection coil winding framework 5 with the axis arranged vertically is arranged. The detection coil winding framework 5 comprises a detection framework main body 15 made of non-magnetic and non-conductive non-metallic materials, and the detection framework main body 15 is of a vertically arranged cylindrical structure; the cylindrical detection framework body 15 is provided with a detection coil forward winding groove 16 and a detection coil reverse winding groove 17 which are sequentially arranged from top to bottom along the vertical axis of the detection framework body 15. The detection coil forward winding groove 16 and the detection coil reverse winding groove 17 are equal in height and depth, and detection coil winding posts 19 having the same outer diameter are disposed in the middle of the detection coil forward winding groove 16 and the detection coil reverse winding groove 17. Therefore, the number of winding turns, the winding length and the number of winding layers of the detection coil forward winding section 23 and the detection coil reverse winding section 24 which are wound in the detection coil forward winding groove 16 and the detection coil reverse winding groove 17 and have different winding directions are ensured to be the same.

Meanwhile, a winding groove isolation section 18 is arranged between the detection coil forward winding groove 16 and the detection coil reverse winding groove 17 of the detection coil winding framework 5. The side part of the winding groove isolation section 18 in the middle of the detection framework main body 15 is provided with a wiring notch 21 which is axially arranged along the detection coil winding column 19, and the upper part of the detection framework main body 15 can also be provided with a lead inlet and outlet 22. The outer end of the wiring notch 21 is arranged at the outer edge of the detection framework main body 15, and the inner end of the wiring notch 21 is radially arranged at the bottom of the detection coil forward winding groove 16 and the detection coil reverse winding groove 17 and the outer wall of the detection coil winding column 19, so that the detection of the layer-by-layer winding of the winding wire (non-magnetic wire) of the winding coil 6 is facilitated, the length of the winding wire arranged along the radial direction is reduced, and the interference is reduced. In addition, the wiring gap 21 is used for conveniently detecting the entering and exiting of the winding coil 6 in the detection coil forward winding groove 16 and the detection coil reverse winding groove 17, the consistent winding number of the detection coil forward winding section 23 and the detection coil reverse winding section 24 is ensured, and the occurrence of fine turn error is effectively avoided.

The detection coil is wound on the detection framework main body 15 of the framework 5 and is also provided with a differential detection winding coil 6; and the detection winding coil 6 is composed of a detection coil forward winding section 23 and a detection coil reverse winding section 24 which are separated from each other by a winding groove separation section 18 in the middle and are continuously arranged in the detection coil forward winding groove 16 and the detection coil reverse winding groove 17. Namely: the detection coil forward winding section 23 of the detection winding coil 6 is wound around the detection coil winding post 19 in the middle of the detection coil forward winding groove 16 of the detection bobbin body 15, and the detection coil reverse winding section 24 connected to the detection coil forward winding section 23 is continuously wound around the detection coil winding post 19 in the middle of the detection coil reverse winding groove 17 of the detection bobbin body 15. The detection coil forward winding section 23 and the detection coil reverse winding section 24 are identical in winding number, winding length, and winding layer number. Therefore, the detection winding coil 6 with a differential structure formed by the same winding is used for detecting weak magnetic signals, and the influence of an environmental magnetic field and an excitation magnetic field on the detection signals is reduced; and the influence of the non-detection coil segment on the detection coil segment is reduced by the winding slot isolation segment 18 arranged between the detection coil forward winding slot 16 and the detection coil reverse winding slot 17.

In order to adjust the relative position in the axial direction between the detection coil bobbin 5 and the sample 4 provided on the sample holder 3, an adjustment structure for adjusting the relative position in the axial direction is provided between the detection coil bobbin 5 and the holder body 12. One form of adjustment mechanism is: the middle part of the bearing seat body 12 of the sample bearing seat 3 is provided with a detection coil mounting groove 13, the detection coil winding framework 5 is positioned in the detection coil mounting groove 13, the middle part of the detection coil winding framework 5 is provided with a detection framework connecting hole 20, and the detection framework connecting hole 20 is connected with a detection framework positioning rod 7 which is vertically arranged in the detection coil mounting groove 13 through threads (as shown in fig. 7). In combination with specific use requirements, the detection coil mounting groove 13 may be disposed in the middle of the upper end of the bearing seat body 12, or may extend from the middle of the upper end to the inside of the bearing seat body 12, and the detection coil mounting groove 13 may also be disposed at the middle axis position of the bearing seat body 12 in a penetrating manner; the detection framework positioning rod 7 can be arranged at the upper end of the supporting connecting block 2 on the base 1, so that the connection and the fixation of the detection framework positioning rod 7 are facilitated. So as to be convenient for the winding framework 5 of the detection coil to be positioned in the detection coil mounting groove 13 of the sample bearing seat 3 through the detection framework positioning rod 7 at the upper end of the supporting connecting block 2. Meanwhile, the inner wall of the detection framework connecting hole 20 in the middle of the detection framework main body 15 of the detection coil winding framework 5 is provided with an internal thread, and correspondingly, the outer wall of the detection framework positioning rod 7 at the upper end of the support connecting block 2 is provided with an external thread matched and connected with the internal thread of the detection framework connecting hole 20. Therefore, the vertical relative position between the detection coil winding framework 5 and the sample 4 on the sample bearing seat 3 outside the detection coil winding framework is changed by utilizing the precise thread structure which is matched and connected between the detection framework connecting hole 20 of the detection coil winding framework 5 and the detection framework positioning rod 7 on the supporting and connecting block 2.

According to the specific use requirement, the adjusting structure for adjusting the axial relative position between the detection coil winding skeleton 5 and the sample bearing seat 3 can also adopt another form: a detection coil mounting groove 13 is formed in the middle of a bearing seat body 12 of the sample bearing seat 3, and the detection coil winding framework 5 is located in the detection coil mounting groove 13; and the detection coil winding framework 5 is connected with the sample bearing seat 3 through threads. The thread connection structure between the detection coil winding framework 5 and the sample bearing seat 3 comprises an external thread arranged on the outer wall of the detection coil winding framework 5, and correspondingly, an internal thread used for being matched with the external thread is arranged on the inner wall of the detection coil mounting groove 13 of the bearing seat main body 12. So that the detection coil winding framework 5 positioned in the detection coil mounting groove 13 is connected with the bearing seat body 12 through threads, and the vertical relative position between the detection coil winding framework 5 and the sample 4 on the bearing seat body 12 is adjusted by utilizing the precise thread structure which is matched and connected between the outer wall of the detection coil winding framework 5 and the inner wall of the detection coil mounting groove 13 of the bearing seat body 12.

Through the adjusting structure, the relative position of the sample 4 and the detection winding coil 6 is finely adjusted, so that the center of a magnetic field generated by exciting the sample 4 on the sample bearing seat 3 is positioned in the middle position between the detection coil forward winding section 23 and the detection coil reverse winding section 24 of the differential detection winding coil 6; namely: the center of a magnetic field generated by exciting the sample 4 and the center positions of the forward winding section 23 and the reverse winding section 24 of the detection coil are positioned on the same horizontal line; thereby offsetting the noise influence caused by the change of the testing environment and leading the detection of the biological marker to be close to the ideal state; in addition, in the process of detecting the sample 4 placed in the detection hole 14 of the sample bearing seat 3, the sample 4 is positioned at the positive center position of the detection coil forward winding section 23 and the detection coil reverse winding section 24 of the differential type detection winding coil 6, so as to ensure that the magnetic induction line generated after the sample 4 is excited passes through the differential type detection winding coil 6 to the maximum extent, and further ensure that the maximum signal value of the detected sample 4 can be detected under the condition that the external excitation signals are the same.

Two groups of excitation coil winding frameworks 8 with axes arranged along the transverse direction and the symmetry direction are respectively arranged on two sides of the supporting connection block 2 on the base 1. The excitation coil winding framework 8 comprises an excitation framework main body 25 made of non-magnetic and non-conductive non-metallic materials, an excitation coil winding groove 26 is formed in the excitation framework main body 25, an excitation coil winding column 27 is arranged in the middle of the excitation coil winding groove 26, and the excitation winding coil 9 is wound on the excitation coil winding column 27 in the middle of the excitation coil winding groove 26; an excitation bobbin base 29 is provided at the lower end of the excitation bobbin main body 25 on which the central axis of the winding coil 9 is excited in the transverse direction. Excitation framework main bodies 25 of the two-side excitation coil winding framework 8 are detachably connected with the side parts of the supporting and connecting blocks 2 through excitation framework bases 29 respectively; and are connected by means of connecting bolts provided in the supporting block connecting holes 30 of the excitation frame base 29 and the excitation frame connecting holes 11 of the side of the supporting connection block 2.

Two excitation winding coils 9 which are continuously arranged along the transverse direction are arranged on the two groups of excitation coil winding frameworks 8 (because the two groups of excitation coil winding frameworks 8 are symmetrically arranged at two sides of the sample bearing seat 3, the excitation winding coils 9 are divided into a left section and a right section), the excitation winding coils 9 are continuously wound on the excitation coil winding columns 27 in the middle of the excitation coil winding grooves 26 of the two groups of excitation coil winding frameworks 8 which are symmetrically arranged, and the winding directions, the winding turns, the winding lengths and the winding layer numbers of the two sections of excitation winding coils 9 are the same; thereby forming a Helmholtz coil structure and generating an excitation magnetic field required by detection. In order to improve the excitation effect, the distance D from the radial center of the excitation winding coil 9 to the central axis of the excitation framework main body 25 is greater than or equal to the distance H between the axial centers of two sections of winding coils on the left and right side excitation coils winding frameworks 8. The left and right ends of the excitation bobbin main body 25 are respectively provided with wiring grooves 38 for facilitating the entry and exit of the windings of the excitation winding coil 9 into and out of the excitation coil winding groove 26, so that the entry and exit of the windings (non-magnetic wires) of the two sections of excitation winding coils 9 are facilitated by the wiring grooves 38 disposed at the two ends of the excitation coil winding groove 26. Meanwhile, the middle part of the excitation framework main body 25 of the excitation coil winding framework 8 is provided with an expansion heat dissipation ring hole 28 which is arranged along the central axis direction of the excitation winding coil 9; and then through the expansion heat dissipation ring hole 28 that the excitation coil twines the middle part setting of skeleton 8, make the operation of placing of detection coil winding skeleton 5 and sample 4 convenient to have enough heat dissipation, thermal-insulated space between excitation winding coil 9 and the detection winding coil 6. Moreover, the uniform strong magnetic field lines generated by the exciting winding coil 9 on the exciting coil winding framework 8 are mutually perpendicular to the middle axis of the detecting winding coil 6 of the detecting coil winding framework 5; and the sample 4 on the sample bearing seat 3 and the detection winding coil 6 on the detection coil winding framework 5 are both in a uniform magnetic field generated by the excitation winding coil on the excitation coil winding framework 8.

In order to reduce the interference of external electromagnetic waves to the detection device, an electromagnetic shielding cover may be disposed outside the sample holder 3 on the base 1 and the excitation coil winding framework 8 symmetrically arranged on both sides. The electromagnetic shielding cover is used for shielding the interference of electromagnetic waves in the environment to the magnetic signal acquisition device, and an electric shielding layer and a magnetic shielding layer are required to be arranged on the electromagnetic shielding cover according to the characteristics of the electromagnetic waves. When the whole device works, eddy current is generated on the electromagnetic shielding cover due to the excitation of the winding coil 9, and the parameters of the excitation winding coil are reversely influenced; when the electromagnetic shielding cover is used, the series and parallel resonance parameters in the circuit are recalculated and matched for use. The distance between the electromagnetic shield and the device is such that the eddy currents generated by the excitation on the electromagnetic shield have as little adverse effect as possible on the excitation winding coil. Meanwhile, in order to reduce the influence of eddy current generated on the electromagnetic shielding cover on the detection device, the external electromagnetic shielding cover can be arranged into a net shape; and in order to achieve the shielding effect, the diameter of the mesh of the reticular electromagnetic shielding cover is smaller than the wavelength of electromagnetic waves in the environment.

The sample 4 comprises a biological functionalized magnetic ball, an antibody buffer solution and a solution of a detected object, the biological functionalized magnetic ball comprises a magnetic core and a hydrophilic coating layer, and a detection antibody which can be specifically combined with the detected object is coupled on the hydrophilic coating layer of the biological functionalized magnetic ball by a biochemical means. The inner diameter of the magnetic core can be 25-50 nm, and the hydrodynamic outer diameter after antibody coupling is 90-150 nm. During detection, the microscopic morphology of the magnetic ball changes due to the combination of the antigen and the antibody, so that the magnetic performance of the magnetic ball is changed, and the magnetic signal variation is captured by the biomarker magnetic signal acquisition device, so that the quantitative detection of trace components in blood is realized; and can detect the components in whole blood, plasma, serum and cell disruption liquid in a liquid phase.

The magnetic sensitive immunity detection device for weak magnetic signal detection by using the magnetic signal acquisition device further comprises a signal generator 33, wherein a reference frequency output end of the signal generator 33 is electrically connected with a reference frequency input end of a phase-locked amplifier 34 for locking frequency, and an excitation signal output end of the signal generator 33 is electrically connected with an excitation signal input end of an excitation power amplifier 35. An excitation signal output end of the excitation power amplifier 35 is electrically connected with an excitation winding coil 9 arranged on an excitation coil winding framework 8 to generate an alternating magnetic field, and then the detection coil is excited to wind the sample 4 in the detection hole 14 in the middle of the upper end of the framework 5 to generate a detected magnetic signal. The detection winding coil 6 is electrically connected to the signal input terminal of the lock-in amplifier 34, and the signal output terminal of the lock-in amplifier 34 is electrically connected to the signal input terminal of the processor. The magnetic signal generated by exciting the sample 4 is detected by a detection winding coil 6 arranged on a detection coil winding framework 5, and the detected electric signal is transmitted to a phase-locked amplifier 34 electrically connected with the detection winding coil 6 and then transmitted to a terminal computer or a cloud end through the phase-locked amplifier 34 for subsequent processing.

In the detection process, an excitation current with higher frequency and higher intensity is required to be applied to the excitation winding coil 9; however, due to the influence of the ac impedance of the excitation winding coil 9, it is impossible to apply an excitation current having a large intensity to the excitation winding coil 9 at a high frequency. Therefore, an excitation series resonance 36 for reducing the alternating-current impedance may be provided between the excitation signal output terminal of the excitation power amplifier 35 and the connection terminal of the excitation winding coil 9; the ac impedance of the excitation circuit is reduced by the excitation series resonance 36 formed by the capacitor, so that the excitation circuit can realize the improvement of the current intensity on the premise of high frequency. In addition, the resonant circuit is mainly designed according to the frequency of the exciting magnetic field and the inductance value of the exciting winding coil 9, and a proper capacitor is selected; the frequency and the current intensity of the circuit can be effectively improved, and the influence of direct current on the whole detection process can be eliminated.

The excitation frequency is determined by the relaxation time of the superparamagnetic nanoparticles, i.e. for superparamagnetic particles which are not bound to the detected object, it is satisfied that the excitation period is much smaller than the denier relaxation time of the superparamagnetic particles and slightly larger than or equal to their brownian relaxation time. Generally, magnetic nuclei above 20nm can meet the Neille relaxation time requirements, while Brownian relaxation times are generally availableτ _B = πηd _H ³/2k _B TIs shown in whichηIn order to obtain the viscosity of the solution,k _B Tin order to be a thermal energy,d _His the magnetic particle hydraulic diameter.

The detection winding coil 6 is used for detecting alternating current magnetization signals generated by magnetic particles, and because the superparamagnetic particles have nonlinear magnetization property, in order to reduce excitation noise interference, a harmonic signal detection method is adopted to detect the signals. The biomarker magnetic-sensitive immunoassay device can detect magnetic particle signals in an odd harmonic or even harmonic mode. When the excitation field is a pure alternating current field, i.e. only alternating current excitation current is passed through the excitation winding coil 9I _acThen, the superparamagnetic particles will generate odd harmonic signals; when the excitation field is an AC/DC coupling field, that is, an AC excitation current and a DC excitation current are simultaneously introduced into the excitation coilI _dcThen, odd and even harmonic signals will be generated simultaneously; preferably, the use of the intensity ratio of the multiple harmonic signal can further reduce the influence of the ambient temperature, the change in the solution viscosity, or the like on the detection signal, and improve the detection sensitivity.

Meanwhile, a detection parallel resonance 37 for filtering and improving the signal-to-noise ratio is further provided between the connection end of the detection winding coil 6 and the detection signal input end of the lock-in amplifier 34. The use of the detection parallel resonance 37 can greatly enhance the detection signal strength and suppress the passage of non-detection signal frequency noise; quality factor available for signal-to-noise enhancementQ = ωL/RIs shown in whichωIn order to detect the angular frequency of the antenna,Lin order to detect the coil inductance,Rthe equivalent direct current resistance of the detection coil is obtained. Therefore, to obtain largerQThe excitation and detection signal frequencies need to be increased. However, as mentioned before, the excitation and detection signal frequencies are determined by the relaxation times of the superparamagnetic nanoparticles. In the traditional alternating current detection, magnetic particles have larger hydraulic diameter, for example, the Brownian relaxation time of the magnetic particles with the particle size of 250nm in pure water solution is about 5.9ms at room temperature, the excitation frequency of the magnetic particles is lower than 169.5Hz, the third harmonic frequency is lower than 508.5Hz, and the resonance detection is carried out at the frequencyQValues often only slightly above 1, the parallel resonance does not have the effect of enhancing the signal-to-noise ratio. Optimized tool for better signal-to-noise ratioSuperparamagnetic particles with smaller hydraulic diameter, such as magnetic particles with the particle size of 90nm, have the Brownian relaxation time of about 0.27ms, the excitation frequency of 3,704Hz and the third harmonic frequency of 11,112Hz, and under the frequency, the quality factor of more than 10 times can be easily obtained.

It will be appreciated that the excitation series resonance 36 provided between the excitation power amplifier 35 and the excitation winding coil 9, and the detection parallel resonance 37 provided between the detection winding coil 6 and the lock-in amplifier 34, may be provided in a separate arrangement or in a simultaneous arrangement, depending on the particular needs of the use. In order to effectively avoid the phenomenon of coil equivalent direct current resistance increase caused by high-frequency eddy current, a detection winding coil 6 and/or an excitation winding coil 9 are manufactured by using a plurality of twisted wires, and under the condition, a quality factor of more than 30 times can be obtained. In addition, a low-temperature cooling system such as liquid nitrogen can be used for further reducing the direct-current resistance of the coil, so that a quality factor of more than 100 times can be obtained, and the signal-to-noise ratio of the detection system is greatly improved.

When the magnetic signal acquisition device and the magnetic sensitive immunity detection device are used, firstly, a sample bearing seat 3 is placed in a bearing seat clamping groove 10 at the upper end of a support connecting block 2, a detection sample 4 is placed at the upper end of the sample bearing seat 3, a detection hole 14 is formed at the periphery of a detection coil mounting groove 13, a detection coil winding framework 5 with a differential detection winding coil 6 is wound, the detection coil mounting groove 13 is formed in the middle of the sample bearing seat 3, the detection coil winding framework 5 is connected with a detection framework positioning rod 7 on the support connecting block 2 by utilizing a detection framework connecting hole 20, and then the detection winding coil 6 can fully detect a magnetic signal generated after the sample 4 outside the detection winding coil is excited by an excitation magnetic field.

Then, starting each detection device, and adjusting background noise in advance; namely: the method comprises the following steps that a detection framework connecting hole 20 of a detection framework 5 is wound by a detection coil, and a precise thread structure which is matched and connected with a detection framework positioning rod 7 on a supporting and connecting block 2 is utilized to change the vertical relative position between the detection coil wound on the framework 5 and a sample 4 on a sample bearing seat 3 outside the detection coil, so that the center of a magnetic field generated by exciting the sample 4 on the sample bearing seat 3 is positioned in the middle position between a detection coil forward winding section 23 and a detection coil reverse winding section 24 of a differential detection winding coil 6; at the same time, the reading of the lock-in amplifier 34 is observed to minimize background noise as much as possible. And the position of the sample bearing seat 3 is adjusted in a rotating way, so that a connecting line between the center of the projection of the sample 4 in the detection hole 14 in the horizontal plane and the center of the projection of the detection winding coil 6 in the horizontal plane is parallel to a uniform magnetic field line generated by the excitation winding coil 9, and the signal value of the sample 4 which can be detected is improved.

After that, the detection of sample 4 is started: adjusting the output waveform, frequency, voltage and current of the signal generator 33 to control the driving signal output by the driving power amplifier 35; the excitation electrical signal output by the excitation power amplifier 35 is transmitted to the excitation winding coil 9, so that the excitation winding coil 9 generates an alternating magnetic field within the range of the sample 4, and the sample 4 is excited by the alternating magnetic field generated by the excitation winding coil 9. Further, since the sample 4 contains the biofunctionalized magnetic ball, the sample 4 generates a magnetic signal matching the excitation signal of the excitation winding coil 9 by the excitation. Then, a magnetic induction line of a magnetic signal generated by the sample 4 penetrates into a detection winding coil 6 positioned in the middle of the sample bearing seat 3, so that the magnetic signal generated by exciting the sample 4 is collected and converted into an electric signal by using the detection winding coil 6; subsequently, the detection winding coil 6 transmits the acquired signal to the lock-in amplifier 34 for preliminary data display. The lock-in amplifier 34 transmits the digital signal to a computer or a PCB for data calculation and storage, and finally displays the processed digital signal in the form of "concentration value of specific trace component in blood" via a display screen, thereby completing the detection of the concentration of specific trace component in blood (the working flow is shown in fig. 14).

Example (b):

as shown in fig. 12 and 13, in operation of the present invention, the illustrated device is used, the signal generator 33 is a WF1948 type signal generator available from NF corporation, the pump power amplifier 35 is a BP4610 type power amplifier available from NF corporation, and the lock-in amplifier 34 is an LI5645 type lock-in amplifier available from NF corporation. Experiment frequency: 2800Hz, experimental current: 12.6A;

	number of single coil turns	Static total resistance	Total inductance
				Detecting a wound coil	702 turns	55.90Ω	17.85mH
Exciting winding coil	240 turns	2.21Ω	33.45mH

In the experiment, the excitation winding coil 9 is energized with an alternating current of a fixed frequency, so that the excitation winding coil 9 generates an alternating magnetic field of which the magnetic field direction is changed at the fixed frequency but the magnetic field magnitude is not changed, thereby magnetizing the sample 4. The relaxation time of the magnetic nanoparticles can be prolonged due to the binding label formed by the binding reaction between the magnetic nanoparticles coupled with the specific antibody and the corresponding antigen; thus, by using their difference in relaxation time, the bound label and the free label are magnetized, and then the two types of magnetism are measured using the third harmonic signal and the magnetic relaxation property; further, from the attenuation of the third harmonic signal and the increase of the magnetic relaxation signal, the concentration of the target can be detected.

Experimental data: magnetic field strength: 8mT, reagent amount of 20ul, reagent concentration of 1mg/ml, magnetic sphere inner diameter of 30nm and magnetic sphere outer diameter of 90 nm.

Signal strength comparison table generated after test sample is excited under different frequencies

Frequency (Hz)	Signal intensity (uV)
		2200	99.11
2400	127.35
		2600	152.53
2800	164.52
		3000	140.51
3200	135.78
		3400	127.52

Experimental data: the magnetic core particle size is 30nm, the magnetic sphere is 40ul, the CRP solution is 5ul, and the magnetic field intensity is as follows: 8 mT. To 40ul of 1mg/ml magnetic spheres, 5ul of CRP antigen was added at different concentrations.

Signal change table after 30s reaction of detection samples under different CRP concentrations

CRP concentration (ng/ml)	Magnetic original signal (uV)	30s Signal (uV) after addition of antigen	Difference (uV)	Percent difference
					200000	155.12	64.38	90.74	58.50%
20000	153.03	106.25	46.78	30.57%
					2000	155.44	134.72	20.72	13.33%
200	150.85	136.85	14	9.28%
					20	149.98	146.34	3.64	2.43%
2	145.57	143.39	2.18	1.50%
					0.2	146.3	144.83	1.47	1.00%
0.1	150.6	149.64	0.96	0.64%

Signal change table after 5min reaction of detection samples under different CRP concentrations

CRP concentration (ng/ml)	Magnetic original signal (uV)	5min Signal (uV) after addition of antigen	Difference (uV)	Percent difference
					200000	155.12	30.6	124.52	80.27%
20000	153.03	80.3	72.73	47.53%
					2000	155.44	121.04	34.4	22.13%
200	150.85	133.4	17.45	11.57%
					20	149.98	142.02	7.96	5.31%
2	145.57	142.52	3.05	2.10%
					0.2	146.3	144.47	1.83	1.25%
0.1	150.6	149.06	1.54	1.02%

As can be seen from the above table, the signal variation of the magnetosphere becomes gradually larger as the antigen concentration increases.

Experimental data: under the conditions of the excitation magnetic field strength of 8mT and the excitation frequency of 2800Hz, the detection result of the CRP antigen with the concentration of 20000ng/ml and the amount of 4 samples is added into 20ul of CRP detection reagent of the detection group. As can be seen, the signal intensity is linearly reduced along with the increase of the total amount of the CRP protein, which indicates that more biological functionalized magnetic nanoparticles are combined with the CRP antigen, and the detection sensitivity can realize the detection of ul-level samples.

Signal intensity comparison table of CRP solution with different content and same concentration added into 20ul detection reagent

CRP solution content (ul)	Signal intensity (uV)
		0	144.9
5	75
		10	55.8
15	28.8
		20	13.2
25	4.2

In the experiment, the signal generator 33 controls parameters of the whole system, the signal generator 33 is not needed, in order to accurately control the frequency and the current, and in the experiment, when only the exciting power amplifier 35 is used due to the thermal noise of the coil and the like, the current or the voltage of the power supply after the frequency is set is increased to a certain degree (the current or the voltage is not reached to the required value), the current or the voltage cannot be changed to increase the other value upwards, so the signal generator 33 is applied. The exciting power amplifier 35 sends out an alternating voltage with a determined frequency to enable the exciting winding coil 9 to generate an alternating magnetic field to magnetize the sample 4, the magnetic signal is detected through the detection winding coil 6, and the concentration of the detected object in the detected solution is digitally displayed through signal processing due to the difference of relaxation time of the free mark and the bound mark.

The excitation magnetic field gives a sinusoidal signal with a certain frequency, and the interference of a fundamental wave signal (primary wave signal) is large, so that the interference of the geomagnetic field, equipment and the like to the fundamental wave signal can be generated; therefore, harmonics of the third order or higher are selected for detection. And because the harmonic signal is continuously reduced along with the increase of the times, the geomagnetic field and equipment have little influence on the third harmonic, so that the third harmonic is selected for detection, and the signal acquisition strength and the signal acquisition precision both meet the requirements required by experiments.

The magnetic-sensing immunoassay device can be applied to the field quantitative rapid detection of trace components (such as myocardial markers, tumor markers, new crown antibodies and other infectious disease markers) in blood plasma, after blood collection, blood is dripped into a magnetic ball solution in a reagent tube, and the reagent tube is placed into a detection hole 14 of the detection device for detection. The device can be applied to various occasions such as families, ambulances, disease investigation places and the like, and can strive for a large amount of treatment time for patients.

Claims

1. A magnetic signal acquisition apparatus comprising an excitation winding coil (9) and a detection body, characterized in that: the detection body comprises a detection winding coil (6) and a detection hole (14) on the sample bearing seat (3), and the detection winding coil (6) corresponds to the detection hole (14); the detection body is positioned in a uniform magnetic field generated by the excitation winding coil (9), and the uniform magnetic field generated by the excitation winding coil (9) is vertical to the central axis of the detection winding coil (6).

2. A magnetic signal acquisition apparatus according to claim 1, wherein: the detection winding coil (6) is wound on the detection coil winding framework (5), excitation coil winding frameworks (8) are symmetrically arranged on two sides of the sample bearing seat (3), and excitation winding coils (9) formed by Helmholtz coils are arranged on the excitation coil winding frameworks (8) on the two sides.

3. A magnetic signal acquisition apparatus according to claim 2, wherein: the detection winding coil (6) adopts a differential winding structure.

4. A magnetic signal acquisition apparatus according to claim 1, wherein: the sample carrying seat (3) can rotate relative to the exciting winding coil (9).

5. A magnetic signal acquisition apparatus according to claim 2, wherein: the detection coil winding framework (5) comprises a detection framework main body (15), a detection coil forward winding groove (16) and a detection coil reverse winding groove (17) are respectively arranged on the detection framework main body (15), and the detection coil forward winding groove (16) and the detection coil reverse winding groove (17) are sequentially arranged along the axis of the detection framework main body (15).

6. A magnetic signal acquisition apparatus according to claim 5, wherein: and a winding groove isolation section (18) is also arranged between the detection coil forward winding groove (16) and the detection coil reverse winding groove (17).

7. A magnetic signal acquisition apparatus according to claim 2, wherein: the detection coil winding framework (5) and the sample bearing seat (3) can adjust the axial relative position.

8. A magnetic signal acquisition apparatus according to claim 7, wherein: the sample bearing seat (3) comprises a bearing seat main body (12), a detection coil mounting groove (13) is formed in the middle of the bearing seat main body (12), and the detection holes (14) are formed in the periphery of an opening in the upper end of the detection coil mounting groove (13); the detection coil winding framework (5) is positioned in the detection coil mounting groove (13), and a detection framework connecting hole (20) is formed in the middle of the detection coil winding framework (5); the detection framework connecting hole (20) is connected with a detection framework positioning rod (7) which is vertically arranged in the detection coil mounting groove (13) through threads.

9. A magnetic signal acquisition apparatus according to claim 7, wherein: the sample bearing seat (3) comprises a bearing seat main body (12), a detection coil mounting groove (13) is formed in the middle of the bearing seat main body (12), and the detection holes (14) are formed in the periphery of an opening in the upper end of the detection coil mounting groove (13); the detection coil winding framework (5) is positioned in the detection coil mounting groove (13), and the detection coil winding framework (5) is connected with the sample bearing seat (3) through threads.

10. A magnetic signal acquisition apparatus according to claim 8 or 9, wherein: the detection well (14) comprises at least two wells of different depths.

11. A magnetic signal acquisition apparatus according to claim 6, wherein: the side part of the winding groove isolation section (18) is provided with a wiring notch (21) which is arranged along the axial direction; the outer end of the wiring notch (21) is arranged at the outer edge of the detection framework main body (15), and the inner end of the wiring notch (21) is radially arranged at the bottom of the detection coil forward winding groove (16) and the detection coil reverse winding groove (17).

12. A magnetic signal acquisition apparatus according to claim 2, wherein: the excitation coil winding framework (8) comprises an excitation framework main body (25) with an annular structure, and an excitation coil winding groove (26) is formed in the excitation framework main body (25).

13. A magnetic signal acquisition apparatus according to claim 1, wherein: the biological sample buffer solution and the analyte solution are characterized by further comprising a sample (4) capable of being matched with the detection hole (14), wherein the sample (4) comprises a biological functionalized magnetic ball, an antibody buffer solution and the analyte solution, the biological functionalized magnetic ball comprises a magnetic core and a hydrophilic coating layer, and a detection antibody is coupled on the hydrophilic coating layer of the biological functionalized magnetic ball through a biochemical means.

14. A magnetic signal acquisition apparatus according to claim 1, wherein: the detection winding coil (6) and/or the excitation winding coil (9) are made using multiple strands.

15. A magnetic signal acquisition apparatus according to claim 1, wherein: an electromagnetic shielding cover is arranged outside the excitation winding coil (9).

16. A magnetic sensitive immunoassay device comprising the magnetic signal acquisition device of claim 1, characterized in that: the device also comprises a signal generator (33), wherein a reference frequency output end of the signal generator (33) is electrically connected with a reference frequency input end of the phase-locked amplifier (34), and an excitation signal output end of the signal generator (33) is electrically connected with an excitation signal input end of the excitation power amplifier (35); the excitation signal output end of the excitation power amplifier (35) is electrically connected with the excitation winding coil (9); the detection winding coil (6) is electrically connected with the signal input end of the phase-locked amplifier (34), and the signal output end of the phase-locked amplifier (34) is electrically connected with the signal input end of the processor.

17. The magnetic-sensitive immunoassay device of claim 16, wherein: an excitation series resonance (36) is arranged between an excitation signal output end of the excitation power amplifier (35) and a connecting end of the excitation winding coil (9), and/or a detection parallel resonance (37) is arranged between a connecting end of the detection winding coil (6) and a detection signal input end of the phase-locked amplifier (34).

18. A detection method using the magnetic sensitive immunoassay device according to claim 17, characterized in that: the method comprises the following steps:

step one, placing a sample (4) in a detection hole (14);

step two, adjusting the output waveform, the frequency, the voltage and the current of the signal generator (33) to control the excitation signal output by the excitation power amplifier (35);

thirdly, transmitting the excitation electric signal output by the excitation power amplifier (35) to the excitation winding coil (9), enabling the excitation winding coil (9) to generate an alternating magnetic field in the range of the sample (4), and enabling the excited sample (4) to generate a magnetic signal matched with the excitation signal of the excitation winding coil (9);

collecting magnetic signals generated by exciting the sample (4) by using the detection winding coil (6), and converting the magnetic signals into electric signals;

fifthly, the detection winding coil (6) transmits the acquired signals to the phase-locked amplifier (34), and then the phase-locked amplifier (34) transmits the digital signals to the processor for data calculation processing and storage; finally, the processed digital signal is displayed in the form of "concentration value of specific minor constituent in blood".

19. The detection method according to claim 18, characterized in that: the method comprises the following steps that firstly, after a sample (4) is placed in a detection hole (14), all detection devices are started, and background noise is adjusted in advance; the vertical relative position between the detection winding coil (6) and the sample (4) on the sample bearing seat (3) is changed, and simultaneously, the reading of the phase-locked amplifier (34) is observed, so that the background noise is reduced to the minimum.

20. The detection method according to claim 18, characterized in that: after the sample (4) is placed in the detection hole (14), the position of the sample bearing seat (3) is adjusted, so that a connecting line between the sample (4) in the detection hole (14) and the center of the projection of the detection winding coil (6) in the horizontal plane is parallel to a uniform magnetic field line generated by the excitation winding coil (9).