200933150 六、發明說明： 【發明所屬之技術領域】 m 本發明係一種有關於低密度脂蛋白感測元件之技術領域’尤 :指一種利用無閘極氮化鎵場效應電晶體及壓電内電場來偵測血液 - 内氧化的低密度脂蛋白質（Oxidized Low density 1 ipoprotein)濃度之氮化鎵製程氧化低密度脂蛋白感測元件。 【先前技術】 0 低密度脂蛋白（Low density lipoprotein)是人艘内血液 運送膽固醇最重要物質，它所運送的低密度脂蛋白膽固賻（ldl-cholesterol)有部份被肝臟使用，有一部份給組織細胞製造細 胞壁與其他所用。當人體血液含有過多的低密度脂蛋白膽固醇 時，它會在心臟的冠狀動脈血管與腦灰管管壁堆積，形成腫塊而 使動脈管腔變小，這就是所謂動脈粥樣狀硬化的形成，結果使冠 動脈血流或腦血管血流灌注心肌，或腦組織的量減少而造成心肌 〇 缺血（氧）或腦缺血（氧）症狀，一旦血管壁的腫塊發生破裂，更會 引發急性血栓的形成，而突然間塞住了整個血管腔造成血流完全 的阻斷，此時引起的症狀就是急性心肌梗塞或腦中風，由於高濃 度的低密度脂蛋白膽固醇（LDL-cholesterol)是心贜病的重要危 險因素，故一般常稱低密度脂蛋白膽固醇為"不好"的膽固醇。 惟’習用醫學檢查使用的電泳法來檢測低密度脂蛋白含量動 辄八個小時，相當耗時，不符合經濟效益’且存在諸多限制與問 題，實有改良之必要。 200933150 【發明内容】 欲解決之技術問題點：高濃度的低密度脂蛋白膽固醇（LDL-cholesterol)是心臟病的重要危險因素，故一般常稱低密度脂 蛋白膽固醇為”不好"的膽固醇，因此檢測高濃度的低密度脂蛋白 膽固醇（LDL-cholesterol)的含量，對於預防與治療心血管疾病 相當重要，然而習用醫學檢查使用的電泳法來檢測低密度脂蛋白 含量動辄八個小時，相當耗時，不符合經濟效益，且存在諸多限 制與問題。 解決問題的技術特點：提供一種氮化鎵製程氧化低密度脂蛋 白感測元件，係為一種氮化鎵高電子移導率場效電晶體元件，係 包括：一無閘極氮化鋁鎵/氮化鎵感測電晶體元件、一測試窗 口、一源極、一沒極、兩金屬連接線與一純化層。其中，該無閘 極氮化紹嫁/氣化錄感測電晶體元件為一蟲晶晶圓結構’該蟲晶 晶圓結構係包括一氮化鎵層與一氮化鋁鎵層，該氮化鋁鎵層係設 於該氮化鎵層上，該氮化鋁鎵層係包括一重量百分比的鋁，該氮 化鋁鎵層係具有一厚度，使其達成晶格匹配；該測試窗口係設於 該屋晶晶圓結構上，該源極係設於該蟲晶晶圓結構上’該源極係 設於該測試窗口的一側；該汲極係設於該磊晶晶圓結構上，該汲 極係設於該測試窗口的另側；各金屬連接線係分別設於該源極與 該汲極上，藉以提供測量之用；該鈍化層係除該測試窗口外，覆 蓋於該無閘極氮化鋁鎵/氮化鎵感測電晶體元件的外表面上；藉 以快速準確且簡易地感測人體内蛋白質氧化程度者。 其中’該蟲晶晶圓結構係以藍寶石為基材’以分子束蟲晶法 (molecular beam epitaxy, MBE)成長製成。 其中，該磊晶晶圓結構係以藍寶石為基材，以有機化學氣相 200933150 沉積法(metalorganic chemical vapor deposition, MOCVD)製成。 其中，該磊晶晶圓結構中的該氮化鋁鎵層的鋁含量的該重量 百分比為17% ，該氮化鋁鎵層的該厚度為45nm。 其中，該磊晶晶圓結構中的該氮化鋁鎵層的鋁含量的該重量 百分比為25% ，該氮化鋁鎵層的該厚度為35nm。 其中，該磊晶晶圓結構中的該氮化鋁鎵層的鋁含量的該重量 百分比為30% ，該氮化鋁鎵層的該厚度為30nm。 其中，該源極的材料係為合金導電材料，該源極的材料係選 自鈦、鋁、鎳、金所組成之歐姆接觸合金材料。 其中，該汲極的材料係為合金導電材料，該汲極的材料係選 自鈦、鋁、鎳、金所組成之歐姆接觸合金材料。 其中，該金屬連接線的材料係為導電材料，該金屬連接線的 材料係選自鈦、金所組成之導電金屬材料。 對照先前技術之功效： 一、 本發明能夠避免習用繁雜的化學檢驗方式並能快速準確且簡 易地感應人體内蛋白質氧化的程度。 二、 本發明能夠同時具有低成本，高環境抵抗力，與低漏電流等 多種功效。 有關本發明所採用之技術、手段及其功效，茲舉較佳實施例 並配合圖式詳細說明如后，相信本發明上述之目的、構造及其特 徵，當可由之得一深入而具體的瞭解。 【實施方式】 請參閱第一圖至第九圖所示，本發明係提供一種氮化鎵製程 氧化低密度脂蛋白感測元件，係為一種氮化鎵高電子移導率場效 200933150 電晶體（High Electron Mobility Transistor，HEMT)元件 (1 0 )，係包括：一無閘極氮化鋁鎵/氮化鎵感測電晶體元 件、一測試窗口（2 0)、一源極與一没極、兩金屬連接線與一 鈍化層。其中’該無閘極氮化鋁鎵/氮化鎵（AlGaN/GaN)感測 電晶體元件係為一磊晶晶圓結構，該磊晶晶圓結構係包括一氮化 鎵層（1 1)與一氮化鋁鎵層（1 2)，該氮化鋁鎵層（1 2) 係設於該氮化鎵層（1 1 )上，該氮化鋁鎵層（1 2 )係包括一 重量百分比的鋁，該氮化鋁鎵層（1 2)係具有一厚度，使其達 〇 成晶格匹配；該測試窗口（ 2 0)係設於該磊晶晶圓結構上；該 源極係設於該蠢晶晶圓結構上’該源極係設於該測試窗口（ 2 0)的一側；該汲極係設於該磊晶晶圓結構上，該汲極係設於該 測試窗口（ 2 0)的另侧’各金屬連接線係分別設於該源極及該 汲極上，該鈍化層係除該測試窗口（2 〇)外，覆蓋於該無閘極 氮化鋁鎵/氮化鎵感測電晶體元件的外表面上，藉以場效電晶體 特性及氮化鋁鎵/氮化鎵之極化效應所產生壓電内建電場達到快 Q 速準確且簡易地感測人體内蛋白質氧化程度。 其中，該磊晶晶圓結構係以藍寶石為基材，以分子束磊晶法 (molecular beam epitaxy, MBE)成長製成。 其中，該磊晶晶圓結構係以藍寶石為基材，以有機化學氣相 "匕積法（metalorganic chemical vapor deposition, mocvd)製成。 其中，該磊晶晶圓結構中的該氮化鋁鎵層（丄2)的鋁含量 的該重量百分比為17% ，該氮化鋁鎵層（12)的該厚度為4 5 n m。 其中，該磊晶晶圓結構中的該氮化鋁鎵層（丄2)的鋁含量 200933150 的該重量百分比為2 5% ，該氮化鋁鎵層（1 2 )的該厚度為3 5 n m ° — 其中，該磊晶晶圓結構中的該氮化鋁鎵層（1 2 )的鋁含量 • 的該重量百分比為3 0% ，該氮化鋁鎵層（1 2 )的該厚度為3 0 n m ° 其中，該源極的材料係為合金導電材料，該源極的材料係選 自鈦、紹、銻、金所組成之歐姆接觸合金材料。 其中’該汲_極的材料係為合金導電材料》該沒極的材料係選 ® 自鈦、鋁、鎳、金所組成之歐姆接觸合金材料。 其中，該金屬連接線的材料係為導電材料，該金屬連接線的 材料係選自鈦、金所組成之導電金屬材料。 此外，針對本發明的詳細實施原理及内容再詳述如下，其 中，氮化鋁鎵/氮化鎵高電子移導率場效電晶體的操作原理是經 由氮化鋁鎵與氮化鎵費米能階的不同並配合氮化鎵材料特有的極 化特性來產生二維電子氣。二維電子氣顧名思義只有二個維度的 空間方向可移動，意即只可在一個平面上移動，而不能在垂直此 〇 平面的方向上移動，舉個自然界中的例子，自然界中也有這種類 似二維電子氣的物質，如石墨，如果在石墨上沿著石墨片方向量 測電阻會遠小於在石墨片與片之間的電阻。在二維電子氣中運動 的特性比三維的特性清楚，且在其中運動的迴旋軌道也是量子化 的，電子只能處於分立的能階中。二維電子可由改變半導體表面 的位能製造出來，形成一個像三角形一樣的位能井。 本發明利用有機金屬化學氣相沉積法（metalorganic chemical vapor deposition, M0CVD)或者分子束蟲晶法 (molecular beam epitaxy, MBE)來控制原子，將原子一層層 200933150 慢慢蟲晶上去，所以可以利用兩種不同材料彼此能隙的不同在異 質接面處造成能帶的突然突起，而造成所要的三角形位能井。 AlGaN/GaN形成一維電子海機制的條件，除了異質接面因能隙的 不同在所造成的位能井以外還有一個條件就是極化效應。氮化 鎵係屬於Wurtzite磊晶結構，此種磊晶為垂直方向非對稱式的 結構，其特色就是在垂直方向有較大的極化效應。極化效應又分 為一類’其中一類為自發極化（Sp0ntaneous polarization)，而另一類則為壓電極化（piez〇electric polarization)。AlGaN/GaN異質接面的極化效應所產生的内 建電場’在AlGaN内部會形成一個向上方向的電場，使的AiGaN 表面會有負電荷層而接近AlGaN/GaN的介面產生一正電荷層， 此正電荷層會引發在GaN中一個濃度相當高的二維電子海，也就 是AlGaN/GaN雨電子遷移率電晶體（High Electron Mobility Transistor ’ HEMT)為什麼不需要摻雜就可以相當大的電流密 度。 本發明利用AlGaN/GaN的異質結構所產生的壓電内建電場 來偵測低密度脂蛋白的氧化程度，其天然型及氧化型低密度脂蛋 白感測液是以NaCl(aq)作為溶劑且PH值介於7〜8之間，在常 溫常壓下將冷藏之低密度脂蛋白以微量滴管滴於感測元件之上 後’並馬上對其進行電性測量，初步已經量測出在天然型低密度 脂蛋白環境下擁有全部的氨基酸根（NH3 + )，電流因為氮化鋁 AlGaN表面正電荷些微的被氨基酸（NH3 + )根排斥而電流些微下 降’但是在因自由基氧化的氧化型低密度脂蛋白環境則因為 A1 GaN表面充滿氫氧根而導致表面正電荷被結合而導致該壓電内 建電場被破壞而產生電流較為明顯地下降，其電流變化的幅度係 200933150 可到達毫安培（mA)等級。 總結而言，首先，本發明能夠避免習用繁雜的化學檢驗方式 並能快速準確且簡易地感應人體内蛋白質氧化的程度。另外，本 發明能夠同時具有低成本，高環境抵抗力，與低漏電流等多種功 效。 前文係針對本發明之可行實施例為本發明之技術特徵進行具 體說明；惟，熟悉此項技術之人士當可在不脫離本發明之精神與 原則下對本發明進行變更與修改，而該等變更與修改，皆應涵蓋 於如下申請專利範圍所界定之範疇中。 【圖式簡單說明】 第一圖：係本發明可行實施例之氮化鎵分子結構示意圖。 第二A圖：係本發明可行實施例之天然型低密度脂蛋白特微 分子示意圖。 第二B圖：係本發明可行實施例之氧化型低密度脂蛋白特微 分子示意圖。 第三圖：係本發明可行實施例之低密度脂蛋白感測元件示意 圖。 第四圖：係本發明可行實施例之感測元件結構剖面示意圖。 第五圖：係本發明可行實施例之將低密度脂蛋白滴定於感測 元件上示意圖。 第六圖：係本發明可行實施例之不同磊晶結構的載子移動率 與通道載子濃度示意圖。 第七圖：係本發明可行實施例之感測元件於不同環境下的電 流變化示意圖。 第八圖：係本發明可行實施例之天然型與氧化型低密度脂蛋 200933150 白量測結果示意圖。 第九圖：係本發明可行實施例之不同濃度的氧化低密度脂蛋 白對應之輸出電流示意圖。 【主要元件符號說明】 (1〇)氮化鎵高電子移導率場效電晶體元件 (11) 氮化鎵層 (12) 氮化鋁鎵層 (2 0)測試窗口200933150 VI. Description of the invention: [Technical field to which the invention pertains] m The present invention relates to a technical field of low-density lipoprotein sensing elements, particularly: a use of a gateless gallium nitride field effect transistor and a piezoelectric phase An electric field to detect a blood-incorporated oxidized low density lipoprotein (Oxidized Low Density 1 ipoprotein) concentration of gallium nitride process oxidized low density lipoprotein sensing element. [Prior Art] 0 Low density lipoprotein is the most important substance for transporting cholesterol in human blood. The low-density lipoprotein cholesterol (ldl-cholesterol) is partially used by the liver. Parts are used to make cell walls and other tissues for tissue cells. When the human blood contains too much low-density lipoprotein cholesterol, it will accumulate in the coronary artery and the cerebral vasculature of the heart, forming a mass and making the arterial lumen smaller. This is the formation of so-called atherosclerosis. As a result, coronary artery blood flow or cerebrovascular blood flow perfusion of the myocardium, or the amount of brain tissue is reduced, resulting in myocardial ischemia (oxygen) or cerebral ischemia (oxygen) symptoms, once the vascular wall mass rupture, it will cause acute thrombosis The formation, and suddenly blocked the entire vascular lumen caused by complete blockage of blood flow, the symptoms caused by this is acute myocardial infarction or stroke, due to high concentration of low-density lipoprotein cholesterol (LDL-cholesterol) is palpitations It is an important risk factor for the disease, so it is commonly referred to as low-density lipoprotein cholesterol as "not good" cholesterol. However, the electrophoresis method used in the medical examination to detect the low-density lipoprotein content for eight hours is quite time-consuming and uneconomical, and there are many limitations and problems that are necessary for improvement. 200933150 [Disclosed] Technical problem to be solved: High concentration of low-density lipoprotein cholesterol (LDL-cholesterol) is an important risk factor for heart disease, so it is generally called low-density lipoprotein cholesterol as "not good" cholesterol. Therefore, the detection of high concentrations of low-density lipoprotein cholesterol (LDL-cholesterol) is important for the prevention and treatment of cardiovascular diseases. However, the electrophoresis method used in medical examinations to detect low-density lipoprotein levels for eight hours. It is quite time-consuming, not economical, and has many limitations and problems. Technical features of the problem: Provide a gallium nitride process oxidized low-density lipoprotein sensing component, which is a high-transmission galvanic field effect of gallium nitride The transistor component comprises: a gateless aluminum gallium nitride/gallium nitride sensing transistor component, a test window, a source, a gate, a two metal connection line and a purification layer. The gate nitriding/gasification recording sensing transistor component is a silicon wafer structure. The silicon wafer structure includes a gallium nitride layer and an aluminum nitride layer. a layer, the aluminum gallium nitride layer is disposed on the gallium nitride layer, the aluminum gallium nitride layer comprises a weight percentage of aluminum, and the aluminum gallium nitride layer has a thickness to achieve lattice matching; The test window is disposed on the roofing wafer structure, and the source is disposed on the crystal wafer structure. The source is disposed on one side of the test window; the drain is disposed on the epitaxial layer In the wafer structure, the drain is disposed on the other side of the test window; each metal connection line is respectively disposed on the source and the drain to provide a measurement; the passivation layer is in addition to the test window. Covering the outer surface of the gateless aluminum gallium nitride/gallium nitride sensing transistor component; thereby quickly, accurately and easily sensing the degree of protein oxidation in the human body. [The silicon crystal structure is sapphire The substrate is grown by molecular beam epitaxy (MBE). The epitaxial wafer structure is based on sapphire and is subjected to metalorganic chemical vapor deposition (2009). Made by MOCVD), wherein the epitaxial wafer The weight percentage of the aluminum content of the aluminum gallium nitride layer in the structure is 17%, and the thickness of the aluminum gallium nitride layer is 45 nm. The aluminum of the aluminum gallium nitride layer in the epitaxial wafer structure The weight percentage of the content is 25%, and the thickness of the aluminum gallium nitride layer is 35 nm. The weight percentage of the aluminum content of the aluminum gallium nitride layer in the epitaxial wafer structure is 30%, the nitrogen The thickness of the aluminum gallium layer is 30 nm, wherein the material of the source is an alloy conductive material, and the material of the source is selected from the group consisting of titanium, aluminum, nickel, and gold, and the ohmic contact alloy material. The material of the pole is an alloy conductive material, and the material of the drain is selected from the group consisting of titanium, aluminum, nickel, and gold. Wherein, the material of the metal connecting wire is a conductive material, and the material of the metal connecting wire is selected from the group consisting of conductive metal materials composed of titanium and gold. Compared with the efficacy of the prior art: 1. The present invention can avoid the complicated chemical test method and can quickly and accurately sense the degree of protein oxidation in the human body. Second, the invention can simultaneously have low cost, high environmental resistance, and low leakage current and other effects. The above-mentioned objects, structures and features of the present invention will be described in detail with reference to the preferred embodiments of the present invention. . [Embodiment] Please refer to the first to ninth figures, the present invention provides a gallium nitride process oxidized low density lipoprotein sensing element, which is a gallium nitride high electron mobility field effect 200933150 transistor (High Electron Mobility Transistor, HEMT) component (10), comprising: a gateless aluminum gallium nitride/gallium nitride sensing transistor component, a test window (20), a source and a immersion , two metal connecting lines and a passivation layer. Wherein the gateless aluminum gallium nitride/gallium nitride (AlGaN/GaN) sensing transistor component is an epitaxial wafer structure, and the epitaxial wafer structure comprises a gallium nitride layer (1 1) And an aluminum gallium nitride layer (12), the aluminum gallium nitride layer (12) is disposed on the gallium nitride layer (11), and the aluminum gallium nitride layer (12) comprises a weight a percentage of aluminum, the aluminum gallium nitride layer (12) having a thickness such that it is lattice-matched; the test window (20) is disposed on the epitaxial wafer structure; the source system The source is disposed on one side of the test window (20); the drain is disposed on the epitaxial wafer structure, and the drain is disposed in the test window The other side of each of the metal wires (20) are respectively disposed on the source and the drain, and the passivation layer covers the gateless aluminum gallium nitride/nitrogen except the test window (2 〇). On the outer surface of the gallium sensing transistor component, the piezoelectric built-in electric field generated by the field effect transistor characteristic and the polarization effect of aluminum gallium nitride/gallium nitride achieves fast Q speed and accurately and easily senses the human body. protein Degree. The epitaxial wafer structure is made of sapphire as a substrate and grown by molecular beam epitaxy (MBE). The epitaxial wafer structure is made of sapphire and is made of metalorganic chemical vapor deposition (mocvd). Wherein the weight percentage of the aluminum content of the aluminum gallium nitride layer (丄2) in the epitaxial wafer structure is 17%, and the thickness of the aluminum gallium nitride layer (12) is 4 5 nm. Wherein the aluminum nitride layer (丄2) in the epitaxial wafer structure has a weight percentage of 25% of the aluminum content 200933150, and the thickness of the aluminum gallium nitride layer (1 2 ) is 35 nm. ° — wherein the aluminum content of the aluminum gallium nitride layer (1 2 ) in the epitaxial wafer structure is 30% by weight, and the thickness of the aluminum gallium nitride layer (1 2 ) is 3 0 nm ° wherein the material of the source is an alloy conductive material, and the material of the source is selected from the group consisting of titanium, bismuth, antimony and gold. Among them, the material of the 汲_ pole is an alloy conductive material. The material of the immersed material is selected from ohmic contact alloy materials composed of titanium, aluminum, nickel and gold. Wherein, the material of the metal connecting wire is a conductive material, and the material of the metal connecting wire is selected from the group consisting of conductive metal materials composed of titanium and gold. In addition, the detailed implementation principles and contents of the present invention are further described below, wherein the operation principle of the aluminum gallium nitride/gallium nitride high electron mobility field-effect transistor is via aluminum gallium nitride and gallium nitride. The difference in energy levels is combined with the polarization characteristics unique to gallium nitride materials to generate two-dimensional electron gas. The two-dimensional electronic gas, as the name implies, has only two dimensions of spatial direction that can be moved, meaning that it can only move in one plane, but not in the direction perpendicular to this plane. As an example in nature, there is such a similarity in nature. Two-dimensional electron gas materials, such as graphite, if measured on the graphite along the direction of the graphite sheet, are much smaller than the resistance between the graphite sheet and the sheet. The characteristics of motion in two-dimensional electron gas are clearer than those of three-dimensional, and the orbits of motion in which motion is also quantized, and electrons can only be in discrete energy levels. Two-dimensional electrons can be fabricated by changing the potential of the surface of the semiconductor to form a well-like well like a triangle. The invention utilizes metalorganic chemical vapor deposition (M0CVD) or molecular beam epitaxy (MBE) to control atoms, and slowly atomizes the atomic layer 200933150, so two can be utilized. The difference in energy gap between different materials causes a sudden protrusion of the energy band at the heterojunction, resulting in a desired triangular potential well. AlGaN/GaN forms a one-dimensional electron-sea mechanism condition, except that the heterojunction has a polarization effect due to the difference in energy gap. The gallium nitride system belongs to the Wurtzite epitaxial structure, and the epitaxial crystal is a vertically asymmetric structure, which is characterized by a large polarization effect in the vertical direction. Polarization effects are subdivided into one class, one of which is Sp0ntaneous polarization and the other of which is piez〇electric polarization. The built-in electric field generated by the polarization effect of the AlGaN/GaN heterojunction will form an upward electric field inside the AlGaN, so that the surface of the AiGaN has a negative charge layer and the interface close to the AlGaN/GaN generates a positive charge layer. This positive charge layer induces a relatively high concentration of two-dimensional electrons in GaN, that is, why the AlGaN/GaN Rain Electron Mobility Transistor (HEMT) does not require doping to achieve a relatively large current density. . The invention utilizes a piezoelectric built-in electric field generated by a heterostructure of AlGaN/GaN to detect the oxidation degree of low density lipoprotein, and the natural type and the oxidized low density lipoprotein sensing liquid are NaCl (aq) as a solvent and The pH value is between 7 and 8. After the cryopreserved low-density lipoprotein is dropped on the sensing element with a micro-dropper at normal temperature and pressure, it is immediately measured and electrically measured. In the natural low-density lipoprotein environment, it has all the amino acid roots (NH3 + ). The current is slightly degraded by the amino acid (NH3 + ) roots due to the positive charge of the aluminum nitride AlGaN surface, but the current is slightly decreased. The low-density lipoprotein environment is caused by the surface positive charge being bound by the surface of the A1 GaN, which causes the piezoelectric built-in electric field to be destroyed and the current is significantly reduced. The magnitude of the current change is 200933150. Ampere (mA) rating. In summary, first of all, the present invention can avoid the complicated chemical test method and can quickly and accurately sense the degree of protein oxidation in the human body. In addition, the present invention can simultaneously have various effects such as low cost, high environmental resistance, and low leakage current. The foregoing is a description of the technical features of the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. And modifications should be covered in the scope defined by the scope of the patent application below. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the molecular structure of a gallium nitride according to a possible embodiment of the present invention. Figure 2A is a schematic representation of a natural low density lipoprotein specific micromolecule of a possible embodiment of the invention. Figure 2B is a schematic representation of an oxidized low density lipoprotein specific micromolecule of a possible embodiment of the invention. Third panel: is a schematic representation of a low density lipoprotein sensing element of a possible embodiment of the invention. Figure 4 is a cross-sectional view showing the structure of a sensing element in a possible embodiment of the present invention. Figure 5 is a schematic representation of titration of low density lipoprotein onto a sensing element in accordance with a possible embodiment of the present invention. Figure 6 is a schematic diagram showing carrier mobility and channel carrier concentration for different epitaxial structures of a possible embodiment of the present invention. Figure 7 is a schematic diagram showing changes in current of sensing elements in different environments in accordance with a possible embodiment of the present invention. Figure 8 is a schematic diagram showing the results of white measurement of natural and oxidized low density fat egg in a feasible embodiment of the present invention. Figure 9 is a schematic diagram showing the output currents of different concentrations of oxidized low density lipoproteins in accordance with a possible embodiment of the present invention. [Main component symbol description] (1〇) Gallium nitride high electron mobility field effect transistor component (11) Gallium nitride layer (12) Aluminum gallium nitride layer (20) test window