基于扩散动力学的电化学生物传感器的设计

为解决电化学生物传感器在液流式小样品检测时,由于微反应器腔体通道高度对电极双电层及扩散动力学的影响,造成测量不稳定的问题,提出一种新的电化学生物传感器.以小样品通道流体动力学及扩散动力学的分析为基础,推导静止液体非稳态扩散过程平面电极扩散层最小厚度,以此为依据设计制作2种不同腔体高度的葡萄糖氧化酶电极微反应器,与开放式无腔的葡萄糖氧化酶电极微反应器一起进行对比试验,实验结果证明,只有当腔体高度大于静止液体非稳态扩散过程平面电极扩散层最小厚度时,扩散作用在非稳态过程中不被外界干扰,酶促反应才能正常进行.

Design of electrochemical biosensors based on diffusion kinetics

When electrochemical biosensors are applied in fluid flowing small sample testing, the testing result is not stable. It is because of the influence of micro-reactors‘ channel height on electrode double layer and diffusion kinetics. So a new design conception is proposed. Through the analysis of hydrokinetics and diffusion kinetics in micro channel, the minimum diffuse layer’s thickness of coplanar electrodes in unstable state diffusion process of immobile liquid was deduced. Based on it, two kinds of glucose oxidase electrodes with different channel height were manufactured and contrasted test was done with glucose oxidase electrodes with no channel. The result indicates that only when micro reactors channel height is higher than the minimum diffuse layers thickness of coplanar electrodes in unstable state diffusion process of immobile liquid, unstable state diffusion process is not disturbed by external factors and enzymatic reaction goes normally.