基于微机电系统(MEMS)技术制备安培型免疫传感器,并利用基于硫醇单层膜的纳米金单层膜自组装技术设计传感器界面,用于固定人免疫球蛋白(IgG)抗体,研制了一种新型的安培型免疫传感器.采用MEMS技术,在硅片上制备微型的三电极系统以及SU-8反应池.基于自组装技术,先在金电极上自组装巯基乙胺单层膜,利用膜上氨基与纳米金共价结合组装纳米金单层膜,得到可用于固定抗体的界面.实验探讨了影响抗体固定的主要实验参数和条件;考察了采用此固定化方法传感器的响应性能,与金电极直接吸附固定法和戊二醛共价交联固定法进行了比较.对IgG检测的实验结果表明,采用纳米金自组装膜固定抗体,具有活性高、非特异性吸附小、检测线性范围宽等优点.并且,基于MEMS技术的安培型免疫传感器具有微型化、与集成电路工艺相兼容、易于实现传感器的阵列化和实时多参数检测等优点.
A novel immunosensor for the detection of immunoglobulin G has been developed by incorporating the micro electro mechanical systems (MEMS) technology for the preparation of micro amperometric immunosensor and the cysteamine (Cys) based gold nanoparticles (nanogold) self-assembled monolayer (SAM) techniques for the immobilization of IgG antibodis. Based on MEMS technology, a three-microelectrode system enclosed in a SU-8 reaction microwell was produced. By using self-assembling technique, a Cys monolayer was then formulated on the Au electrode to assemble a nanogold monolayer. Thus, an interracial design of Au/Cys/nanogold was prepared and used to immobilize IgG antibodies to detect IgG in human serum. The main conditions of the immobilization of IgG antibodies were investigated. Compared with the direct gold attachment procedure and the glutaraldehyde crosslinking procedure, the developed procedure shows improved features including larger amount and higher immunoactivity of the immobilized antibody, lower nonspecific adsorption and broader linear range for the detection of IgG. Moreover, immunosensor based on MEMS technology has attractive advantages, such as miniaturization, compatibility, easier to be designed into microarrays and to realize the simultaneously multi-parameter detection.