摘要
纳米叉指电极在应用到蛋白质芯片免疫检测中时,由于指端效应和扩散场不连续性造成测量的不稳定,针对此问题,提出一种双螺旋线微电极的设计思路和方案,推导了该电极的稳态扩散电流方程.与叉指微阵列电极相比,双螺旋线微电极具有电场连续、扩散电流特性良好、所占面积小等优势,有利于微型化发展,特别在纳米尺寸时其优点更为明显.在此理论分析基础上,设计实验将双螺旋线微电极应用到蛋白质芯片免疫反应电测中,并采用自组装的方法将金纳米粒子-抗原-抗体复合体和双螺旋线微电极匹配形成三维纳米网络结构,形成一种近似于“半导体”效应的“生物放大”机制,从而提高检测灵敏度.实验结果表明,该设计方案可测量低浓度(10-10g/mL)的抗原,为蛋白质芯片直接电测技术提供了一种可行的途径.
Due to finger-end effects and edge effects, the current diffusion fields of interdigital （IDT） array microelectrodes are discontinuous. So the experimental measurement results are instable and imprecise when IDT array nanoelectrodes are applied on the electronic detection of immunoreactions using protein biochip. A novel design of bispiral microelectrodes was presented. The diffusing current equation at stable state was deducted. Compared with IDT array microelectrodes, bispiral microelectrodes offer advantages of continuous electric fields, good diffusing current characteristics and limited space, which are distinct at nano scale. The performance of bispiral microelectrodes applying on electronic detection of immunoreactions was tested. Gold-nanoparticle labeled antibody was immobilized on bispiral microelectrodes using self assemble method. 3D nano networks were formed after ＂sandwich＂ structure complex of gold nanoparticles-antibody-antigen matched bispiral microelectrodes. Micro-current on bispiral microelectrodes reflects the electrons transfer between the complex and the microelectrodes. The“semiconductor” effect based bioamplification can increase the sensitivity of immunosensor. Experimental result shows that low concentration antigen at 10 10 g/mL level can be measured, which provides potentiality for direct electronic detection of immunoreactions using protein biochip.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2005年第7期957-961,共5页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(30070218).
关键词
叉指微电极阵列
双螺旋线微电极
扩散电流
蛋白质芯片
纳米金
interdigital microelectrode array bispiral microelectrode diffusing current protein biochip gold nanoparticle
