Kim Sang Kyung, Hesketh Peter J, Li Changming, Thomas Jennifer H, Halsall H Brian, Heineman William R
Georgia Institute of Technology, Bioengineering Program, School of Mechanical Engineering, Atlanta, GA 30332, USA.
Biosens Bioelectron. 2004 Nov 1;20(4):887-94. doi: 10.1016/j.bios.2004.04.004.
This research is directed towards developing a more sensitive and rapid electrochemical sensor for enzyme labeled immunoassays by coupling redox cycling at interdigitated electrode arrays (IDA) with the enzyme label beta-galactosidase. Coplanar and comb IDA electrodes with a 2.4 microm gap were fabricated and their redox cycling currents were measured. ANSYS was used to model steady state currents for electrodes with different geometries. Comb IDA electrodes enhanced the signal about three times more than the coplanar IDAs, which agreed with the results of the simulation. Magnetic microbead-based enzyme assay, as a typical example of biochemical detection, was done using the comb and coplanar IDAs. The enzymes could be placed close to the sensing electrodes (approximately 10 microm for the comb IDAs) and detection took less than 1 min with a limit of detection of 70 amol of beta-galactosidase. We conclude that faster and more sensitive assays can be achieved with the comb IDA.
本研究旨在通过将叉指电极阵列（IDA）处的氧化还原循环与酶标记物β-半乳糖苷酶相结合，开发一种用于酶联免疫分析的更灵敏、快速的电化学传感器。制备了具有2.4微米间隙的共面梳状IDA电极，并测量了它们的氧化还原循环电流。使用ANSYS对不同几何形状电极的稳态电流进行建模。梳状IDA电极增强的信号比共面IDA电极大约高三倍，这与模拟结果一致。作为生化检测的一个典型例子，基于磁微珠的酶分析使用梳状和共面IDA电极进行。酶可以放置在靠近传感电极的位置（梳状IDA电极约为10微米），检测时间不到1分钟，β-半乳糖苷酶的检测限为70 amol。我们得出结论，使用梳状IDA可以实现更快、更灵敏的检测。
