一种新型的光寻址电位传感器研究

依据光寻址电位传感器(LAPS)工作原理和光生载流子在硅片中扩散理论,提出了一种正面光照的LAPS新结构设计,在正面光照方式的测量池、插件式芯片和硅尖阵列芯片等方面具有创新性.新型LAPS的光电流信号比背面照射的提高了4倍;在检测标准缓冲溶液pH4.00、pH6.86、pH9.18的pH值时,线性相关系数0.9999,灵敏度为50.1mV/pH.重复检测pH9.18标准缓冲溶液四次的标准偏差和变异系数分别为0.57mV、0.048%.最后,分析讨论了三电极测量方法和新型LAPS结构特色、以及LAPS电解质电导对光电流的影响等.

A New Type of Light Addressable Potentiometric Sensors

Based on the working principle of the light addressable potentiometric sensors (LAPS) and the diffusion theory about the photo-carrier in a silicon chip,a design of the new LAPS structure was advanced newly,with the measuring cell by front illumination,the quickset of LAPS array chip and the silicon tips array.The photocurrent signal of the new LAPS is five times photocurrent of the LAPS by back illumination.When this sensor was used for determining pH value in buffer solution of pH 4.00,pH 6.86,pH 9.18,the correlation coefficient is 0.9999,the response sensitivity is 50.1mV/pH,the standard deviation and variation coefficient for 4 times performances response to buffer solution of pH 9.18 were found to be 0.57mV and 0.048% respectively.Finally,this paper analyzed and discussed the testing method of three electrodes,feature of the new LAPS and the infections of conductance of waiting testing electrolyte on photocurrent.