基于MEMS技术的安培酶免疫传感器研究

该文采用MEMS工艺制备可集成安培酶免疫传感器，用于人免疫球蛋白IgG的检测。该传感器以硅作为基底，铂作为电极，工作电极敏感面积1mm2。SU-8胶形成的微反应池结构使该传感器试剂用量仅为l量级。聚吡咯作为酶与电极之间的电子转移基体聚合于工作电极敏感表面，戊二醛作为交联剂进行抗体(羊抗人IgG)的固定。抗体与酶标抗体(辣根过氧化物酶HRP标羊抗人IgG)对人IgG进行特异性夹心识别，通过检测酶标HRP对底物H2O2催化产生的电流信号实现免疫检测。该传感器工作电压-0.3V，检测下限5ng/ml，线性范围5～255ng/ml，响应时间3min，具有响应快、下限低、试剂用量少、微型化、便于集成等优点。

A Micro Amperometric Immunosensor Based on MEMS

A micro amperometric immunosensor is fabricated to detect human IgG based on MEMS. The Pt electrode is deposited on silicon wafer with the sensitive area of 1 mm². A micro reacting pool is made of SU-8 polymer and several microlitre reagent was needed. Polypyrrole is electropolymerized on the electrode to transfer the electron between the electrode and the enzyme. Glutaraldehyde is used to bind the antibody on polypyrrole. Human IgG is specifically recognized by goat anti-human IgG and horseradish peroxidase (HRP) conjugated goat anti-human IgG in sandwich way. Human IgG is scaled by detecting the current from the catalyzed reaction between HRP and H₂O₂. With the working potential of &;#61485;-0.3V, the immunosensor displayed a good linear dose–response behavior for human IgG concentrations between 5 and 255ng/ml.A low detection limit of 5ng/ml and 3-minute response time are achieved. This micro amperometric immunosensor has many advantages such as fast response time, low detection limit, little reagent, micro bulk and easy integration with IC.