设计并制作了结构尺寸为毫米量级的A1GaN/GaN高电子迁移率晶体管(HEMT)生物传感器,采用数值分析的方法分析了器件传感区域长度与宽度比值及待测物调控二维电子气(2DEG)距离与感测信号之间的关系,给出了结构尺寸为毫米量级的A1GaN/GaNHEMT生物传感器的设计依据,以不同浓度的前列腺特异性抗原(PSA)为待测物,对制作的A1GaN/GaNHEMT生物传感器进行了初步测量,测试结果表明,在50mV的电压下,毫米量级的A1GaN/GaNHEMT生物传感器的对PsA的探测极限低于0.1pg/m1.实验表明毫米量级的A1GaN/GaNHEMT生物传感器具有灵敏度高,易于集成等优点,具备良好的应用前景.
In order to enhance the performance of A1GaN/GaN high electron mobility transistor (HEMT) biosensor, millimeter grade AIGaN/GaN HEMT structure have been designed and successfully fabricated. Factors influencing the capability of the A1GaN/GaN HEMT biosensor are analyzed. UV/ozone is used to oxidize GaN surface and then 3-aminopropyl trimethoxysilane (APTES) self-assembled monolayer can be bound to the sensing region. This serves as a binding layer in the attachment of prostate specific antibody (anti-PSA) for prostate specific antigen detection. The millimeter grade biomolecule-gated GaN/A1GaN HEMT sensor shows a quick buffer solution is added to the antibody-immobilized sensing response when the target prostate specific antigen in a area. The detection capability of this biomolecule-gate sensor estimated to be below 0.1 pg/ml level using a 2 ~ 1.5 mm2 sensing area, which is the best result of GaN/A1GaN HEMT biosensor for PSA detection till now. The electrical result of the biomolecule-gated GaN/A1GaN HEMT biosensor suggests that this biosensor might be a useful tool for the prostate cancer screening.