Electrochemical Analysis 电化学分析

Electrochemical detection based on complex microarray electrodes

In electrochemical analysis, the method and configuration of electrodes play key roles.  Employing a strategy with programmed application of external stimulating potential to separate the time access to electrode surface of targets and interferents, we are able to selectively detect dopamine in the presence ascorbic acid.  Furthermore, lithographic-based microfabrication technology is excellent in preparing functional electrodes. We design and fabricate plane-recessed microelectrode array to increase the detection selectivity and sensitivity of dopamine and pyrocatechol based on interferent-depleting and redox cycling mechanism. We are now exploring and improving the detection performance by utilizing electrochemical bipolar principle and optimizing the size and configuration of chip-based microelectrode device.

基于芯片的阵列微电极检测方法

在电化学检测中，方法和电极构型起着至关重要的作用。我们首先在裸单电极上，通过设计特殊的程序化电位激励信号，分离干扰物和待测物到达电极表面的时间，实现了多巴胺的选择性检测。进一步，我们利用光刻微加工技术制备兼具选择性和高灵敏性的平面-凹微盘阵列双层复合电极（图1），实现了扩散层除杂和氧化还原循环增强下的有机小分子如多巴胺、邻苯二酚的选择性检测（图2）。目前， 我们希望通过对平面-凹微盘阵列电极的构型进行改进，并利用电化学双极性原理，发展基于芯片的复合微电极检测方法， 提高器件的检测能力，

Biomembranes and biomolecule

Cell membrane, which is an important component of cell, plays a key role in metaboly, identification, and signal transduction. Black lipid membrane (BLM), as an ideal biomimetic model for complex biological membranes, provides a platform for investigating the function of selected protein-embedding biomembrane such as ion channels, ion pumps, and receptors. We construct biomimic membranes on a glass nanopore and nanoporous silicon nitride membranes, and combine electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) to study the electrical and mechanical properties of nano-BLMs. Furthermore, single ion channel recordings of a-hemolysin (a-HL), gramicidin and ATPase incorporated into BLMs are detected, and corresponding biosensors are carried out. In addition, in collaboration with Prof. Chao-Yong Yang of our college, we investigate inter- and intramolecular interactions of biomolecules at single molecule level by employing AFM force curve measurements.

基于纳米孔的生物仿生膜

细胞膜是细胞重要的组成部分，它对细胞的物质交换、细胞识别、信号传导等功能的实现都具有重要的意义。由于细胞膜的复杂性，要对其进行直接研究较为困难，因此通常采用人工生物膜来进行生物仿生膜研究。我们组将磷脂双层膜搭建于玻璃纳米孔和硅基纳米孔上，并结合电化学技术和原子力显微镜（AFM）， 对磷脂双层膜的电学和力学性质进行研究。在此基础上，进一步将离子通道蛋白（a-HL、gramicidin、ATPase）嵌入磷脂双层膜中，实现单通道电流检测并进行生物传感。 此外，与我院杨朝勇教授合作，我们利用AFM力曲线的测量， 在单分子水平上研究生物分子内和生物分子间的作用。

Electrochemical pH alteration technique

Solution pH plays critically important roles in a variety of chemical and biological processes. We develop an electrochemically driven pH alteration method based on the concept of a serial electrolytic cell involving a hydrogen permeable Pd thin foil, which allows solution pH to be altered periodically between acid an alkali, and demonstrat its application in acid-base driven DNA denaturation and renaturation, which lays the basis for the possible naissance of the electrochemical acid-base driven polymerized chain reaction (PCR) or other biosensor technique in the future.

大范围原位循环电化学pH调控

溶液pH对多数化学反应和生物过程的顺利进行起着重要的作用。本小组基于透氢钯膜搭建串联双室pH调控平台，利用电化学方法实现对溶液pH进行大范围的酸碱循环调控。基于此，本小组将该平台结合谱学方法实现了对DNA解链变性和复性的观察、提出了电化学驱动DNA酸-碱 PCR概念并进行了前期研究。 未来，该体系还将被用于包括双耦合纳米离子的分离和复合调控在内的各种化学和生物传感。