A kind of glucose sensor of Novel free xylose interference
Technical field
The utility model belongs to technical field of medical equipment, be related to the glucose sensor in a kind of blood sugar test equipment with
And a kind of glucose sensor that test method more particularly to Novel free xylose interfere.
Background technique
The biosensors such as glucose sensor are usually to be formed on insulating properties substrate including working electrode and to electrode
Electrode system, and mix enzyme and electron mediator on it etc. and constitute reagent layer;Usually used electron mediator is the potassium ferricyanide
With the compound of ruthenium etc..
The enzyme that common glucose sensor uses currently on the market experienced from glucose oxidase (GOD) to glucose
Dehydrogenase (GDH) transformation process, initially use GOD due to the interference effect by the oxygen in blood it is larger and gradually by
Not replaced the GDH by oxygen interference effect.
GDH common at this stage substantially there are three types of: with nicotinamide adenine dinucleotide (NAD) be coenzyme NAD-GDH,
It is the FAD-GDH of coenzyme with PQQ-GDH that pyrroloquinoline quinone (PQQ) is coenzyme and with flavin adenine dinucleotide (FAD) (FAD).
It is wherein most of to all employ FAD-GDH, but its influence interference that will receive Xylose Content in blood.
However glucose sensor is made as the electron mediator of FAD-GDH six ammino ruthenium of tri-chlorination is used alone
In the case of, the current value dependent on concentration of glucose in blood sample can not be preferably obtained, leads to not accurately measure blood glucose
Value.
In addition, hematocrit is embodied in hematocrit than low than influencing blood sample in the diffusion of reagent layer
When 42%, the test electric current that glucose generates in blood sample is bigger than normal;And when hematocrit ratio is higher than 42%, blood sample
The test electric current that glucose generates in this is less than normal, therefore the influence that hematocrit contrastive test generates also can't be ignored.
Summary of the invention
In order to overcome shortcoming and deficiency existing in the prior art, the purpose of this utility model is to provide a kind of Novel frees
The glucose sensor of xylose interference has the advantages that agent prescription optimization, reasonable in design and detection accuracy are high.
The technical scheme adopted by the utility model to solve the technical problem is as follows:
A kind of glucose sensor of Novel free xylose interference, the sensor include:
Substrate layer (1);
Electrode layer (2) on substrate layer (1), electrode layer (2) include red blood cell hematocrit than test job electrode (21),
To electrode (22) and blood sugar test working electrode (23), red blood cell hematocrit shares described to electrode than test and blood sugar test
(22);
Insulating layer (3) on electrode layer (2), insulating layer (3) is in the red blood cell hematocrit than test job electrode
(21) there are first window (31) for working portion, in the work department to electrode (22) and blood sugar test working electrode (23)
Fractionation has the second window (32);
The reagent layer (4) being covered on the second window (32);
Hydrophilic interval combination layer (5) on reagent layer (4), hydrophilic interval combination layer (5) is in the first window
(31) notch that is equipped with corresponding with the second window (32) position constitutes reaction zone (51);
Masking tape layer (6) on hydrophilic interval combination layer (5).
Further, the electrode layer (2) further includes sample detection electrode (24) and booting detecting electrode (25), sample introduction inspection
The working portion for surveying electrode (24) is exposed at second window (32), described to electrode (22) and sample detection electrode (24)
Access is formed by the booting detecting electrode (25).
Further, the hydrophilic film in the hydrophilic interval combination layer (5) is handled by single side hydrophily.
Further, the masking tape layer (6) is equipped with notch (61) in the correspondence reaction zone (51) terminal position.
Further, the electrode material of the electrode layer (2) is carbon, and lead material is carbon or noble metal.
The method for exempting from the glucose sensor test of xylose interference using the utility model is as follows:
Step 1, it is switched on after draw blood sample, when forming access to electrode and blood sugar test working electrode and electric current reaches
When the threshold value of setting, the record time is t1, and in the time △ t of setting, blood sugar test working electrode sample detection electrode is formed
When access and electric current reach the threshold value of setting, the record time is t2;
Step 2, blood sample is tested than test job electrode and to alternating voltage is applied between electrode in red blood cell hematocrit
Impedance value, conversed by impedance value, the red blood cell hematocrit ratio of blood sample;
Step 3, after above-mentioned testing impedance, applying DC voltage between electrode and blood sugar test working electrode,
Test the glucose current value of blood sample;
Step 4, it is mended accordingly according to the glucose current value that the red blood cell hematocrit of blood sample compares blood sample
It repays, then converses blood glucose value.
Preferably, red blood cell hematocrit than test job electrode and between electrode apply alternating voltage be 20-100Hz,
200-500mV;To application 200-500mV DC voltage between electrode and blood sugar test working electrode;It further include sample detection function
Can: when draw blood sample deficiency, instrument can report an error.
The beneficial effects of the utility model are as follows:
(1) electrode layer of the utility model sensor is made of multi-electrode, and wherein insulating layer first window limits red blood cell
Hematocrit accurately controls the carbon electrode area of each sensor, is contacted, mentioned with blood sample by exposed window than test job electrode
The high accuracy of testing impedance.Follow-up red blood cell hematocrit contrastive test electric current compensates, and obtains final blood glucose value, mentions significantly
The high accuracy of blood sugar test.In addition, pair to electrode and glucose current test by red blood cell hematocrit than test electrode
Electrode carries out shared, reduces electrode using number, reduces process complexity, improve the stability of glucose sensor.
(2) enzyme that the utility model sensor uses is FAD-GDH, substitutes common GOD, fundamentally avoids oxygen
The influence to test result is pressed, so that the test result of capillary blood and venous blood is almost the same.
(3) although enzyme that the utility model sensor uses is FAD-GDH, but by the optimization to formula system, very
Just accomplishing that system exempts from xylose interference on the basis of originally exempting from the interference of the classes glucose such as maltose, galactolipin.
(4) the utility model sensor selects six ammino ruthenium of tri-chlorination as the first electron mediator, and PES is as the second electronics
Mediator replaces the common potassium ferricyanide, Ferrocene and its derivative, and potassium ferricyanide storage is unstable, is easy to be reduced into ferrous iron
Potassium cyanide, so that glucose sensor closing on the effect phase, background current is increasing, and test result is caused deviation occur,
Especially in low strength range, test result inaccuracy.And six ammino ruthenium of tri-chlorination and PES be as electron mediator, it is water-soluble compared with
Good, the background current of made glucose sensor is smaller and as closing on for phase of effect almost changes smaller, glucose sensing
The stability of device improves the accuracy of test.
(5) the utility model sensor increases detecting electrode, and when blood sample sample introduction deficiency, instrument will report an error, sample introduction
Measurement error caused by detection function is effectively reduced because of sample introduction deficiency.
Detailed description of the invention
Fig. 1 is the glucose sensor hierarchicabstract decomposition structural schematic diagram of the utility model embodiment;
Fig. 2 is the glucose sensor electrode layer distribution schematic diagram of the utility model embodiment;
Fig. 3 is the glucose sensor test value of the utility model embodiment and the linear graph of YSI2300 test value;
Fig. 4 be the utility model embodiment glucose sensor simulation xylose interference test value with compare test value
Comparison diagram;
Wherein, 1- substrate layer, 2- electrode layer, 21- red blood cell hematocrit is than test job electrode, and 22- is to electrode, 23- blood glucose
Test job electrode, 24- sample detection electrode, 25- booting detecting electrode, 3- insulating layer, 31- first window, the second window of 32-
Mouthful, 4- reagent layer, the hydrophilic interval combination layer of 5-, 51- reaction zone, 6- masking tape layer, 61- notch.
Specific embodiment
The utility model is described further with reference to the accompanying drawings and examples.
As depicted in figs. 1 and 2, the glucose sensor of the present embodiment includes: substrate layer 1, electrode layer 2, insulating layer 3, examination
Oxidant layer 4, hydrophilic interval combination layer 5 and masking tape layer 6.
Specifically, the glucose sensor of the present embodiment includes substrate layer 1;Electrode layer 2 on substrate layer 1, electrode
Layer 2 includes the conducting wire of the electrode structure and connection instrument for reaction test;Insulating layer 3 on electrode layer 2, wherein insulating
Window at two is provided on layer 3;The reagent layer 4 of covering on the insulating layer 3;The hydrophilic interval being covered on insulating layer 3 and reagent layer 4
Combination layer 5;The masking tape layer 6 being covered on insulating layer 3 and hydrophilic interval combination layer 5.
Wherein, electrode layer 2 works equipped with red blood cell hematocrit than test job electrode 21, to electrode 22, blood sugar test electric
Pole 23, sample detection electrode 24, booting detecting electrode 25 and the conducting wire connected for electrode with instrument.
Than the working portion of test job electrode 21, there are first windows 31 in red blood cell hematocrit for insulating layer 3, to electrode
22, there are the second windows 32 for the working portion of blood sugar test working electrode 23 and sample detection electrode 24, and in the second window 32
Upper covering reagent layer 4, i.e. reagent layer 4 are covered on the second window 32, cover exposure in full second window 32 to electrode 22, blood
Sugared test job electrode 23 and sample detection electrode 24.
Hydrophilic interval combination layer 5 is equipped with notch in first window 31 and 32 position corresponding section of the second window by double-sided adhesive
Constitute reaction zone 51.Masking tape layer is equipped with notch 61 in 51 end of reaction zone.
By insulating layer 3 there are first window 31 and the second window 32 control test when carbon electrode work area, mention
High red blood cell hematocrit is than testing and the accuracy of glucose test.
By insulating layer 3 there are the second window 32 on cover reagent layer 4, be effectively controlled reaction zone reagent layer 4
Consistency, improve the precision of glucose sensor.
After glucose sensor is inserted into test equipment, start test equipment.By siphonic effect draw blood sample, when
To electrode 22 and the formation access of blood sugar test working electrode 23 and when electric current reaches given threshold, the record time is t1, is being set
In time △ t, when blood sugar test working electrode 23 and the formation access of sample detection electrode 24 and electric current reach given threshold, record
Time is t2 (t2 < t1+ △ t).Than test job electrode 21 and apply 20- between electrode 22 in red blood cell hematocrit at this time
100Hz, 200-500mV alternating voltage test the impedance value of blood sample, and the red blood cell pressure of blood sample is conversed by impedance value
Product ratio.After testing impedance, surveyed in blood sugar test working electrode 23 and to 200-500mV DC voltage is applied between electrode 22
Try the glucose current value of blood sample, the environment temperature measured further according to the red blood cell hematocrit ratio and temperature sensor conversed
Degree is corrected compensation to glucose current value, and converses blood glucose value and show.
Mentioned reagent layer 4 includes following (in parts by weight):
Said components configuration is sufficiently stirred after completing, so that component sufficiently dissolves dispersion, forms homogeneous solution.Its
In, buffer system such as sodium citrate, sodium succinate, bell phthalate buffer, fumaric acid sodium etc.;Hydroxyethyl cellulose plays polymer
The effect of bracket facilitates the dispersion and stabilization of enzyme, while the adhesion of Contrast agent layer;Disintegrating agent such as polyvinylpyrrolidone
PVP promotes dry reagent layer to be disintegrated dispersion in time in blood sample introduction, improves the dispersion rate of reagent layer in blood, anti-
Area is answered quickly to construct the reaction system of homogeneous liquid phase;Surfactant such as Triton increases examination as both sexes surfactant
The hydrophily of oxidant layer 2 improves the fill rate of blood sample.Glucose dehydrogenase FAD-GDH is touched in blood sample
Glucose is oxidized to gluconic acid after glucose, while releasing electronics, passes to six ammino of the first electron mediator tri-chlorination
The ruthenium of ruthenium, trivalent is reduced into the ruthenium of divalent, and then the ruthenium of divalent is oxidized to trivalent ruthenium under 200-500mV DC voltage,
It releases electronics and by electrode Acquisition Detection simultaneously, obtains current value, complete entire electrochemical reaction process, and the second electronics is situated between
Body PES improves the rate on electron transmission to ruthenium and being electrochemically reacted, and accelerates entire electrochemical reaction process.Other
Stabilizer such as maltitol, protein protective agent etc., protective agent of the maltitol as enzyme, improves the stabilization of glucose sensor
Property.
The material of reagent layer 2 mainly includes glucose dehydrogenase FAD-GDH, ruthenium compound and the second electron mediator, ruthenium
Conjunction object is six ammino ruthenium of tri-chlorination, and the second electron mediator is preferably azophenlyene sulfovinate (PES);Glucose dehydrogenase FAD-
The enzymatic activity of GDH is in 200~600U/mg.
The material of substrate layer 1 is polyethylene terephthalate.The electrode material of electrode layer 2 is carbon, and lead material can be with
It can also be the noble metals materials such as gold, it is preferred that lead material is silver for carbon.The material of insulating layer 3 is polyacrylic acid tree
Rouge.
The double-sided adhesive material of hydrophilic interval combination layer 4 is modified acrylic acid, and hydrophilic film is by single side hydrophilic treated
Polyethylene terephthalate.
Above-mentioned glucose sensor tests the blood sample of 11 parts of different concentration of glucose at room temperature.When test
The red blood cell hematocrit ratio of venous blood sample is first adjusted to 42% ± 2%, blood partial pressure of oxygen is adjusted to oxygen saturation, Mei Genong
Blood sample retest 10 times for spending gradient, are averaged.
Glucose sensor test result is shown in Table 1, by comparing with YSI2300 test result it is found that glucose sensor
Test result deviation very little, accuracy is very high.In addition to because being less than 20mg/dL and being greater than 600mg/dL display LO and HI, 20
For the coefficient of variation CV of the test value of blood sample between~600mg/dL within 3%, precision complies fully with requirement.
Table one: glucose sensor test result
Fig. 3 is the linear graph of glucose sensor test value Yu YSI test value, fit equation y=0.9936x+
1.3111 R2=0.9996.Know that the glucose sensor is linearly good.
Above-mentioned glucose sensor tests the blood sample of different concentration of glucose difference xylose concentrations at room temperature.
Blood sample partial pressure of oxygen is adjusted to oxygen saturation, each blood sample than adjusting to 42% ± 2% by the hematocrit of blood sample before test
Test 10 times records test value.
For above-mentioned blood sample on the basis of the identical concentration of glucose of same volume, addition same volume difference xylose is dense
The aqueous solution of degree, the blood sample for being configured to the identical concentration of glucose difference xylose concentration of same volume are tested.Above-mentioned Portugal
The test result of grape sugar sensor is shown in Table two.
Table two: glucose sensor xylose influences experimental results.
Fig. 4 is test data statistical chart of the glucose sensor in xylose influence experiment, and abscissa is that 3 glucose are dense
Gradient is spent, ordinate is the blood sample test result of different xylose concentrations under same concentration of glucose in the accounting of the two summation, can
Know that the blood sample test result of the different xylose concentrations under identical concentration of glucose is almost consistent, deviation is within 3%, to grape
The influence very little of sugared sensor.
The foregoing is merely the preference embodiments of the utility model, do not constitute to scope of protection of the utility model
It limits.Any any modifications, equivalent replacements, and improvements made within spirit of the present utility model and principle etc. should all include
Within the claims of the utility model.