基于浮栅OECT传感的归一化灵敏度优化

Optimization of Normalized Sensitivity Based on Floating Gate OECT Sensing

浮栅有机电化学晶体管(OECT)作为一种新兴的传感检测平台,由于其工作电压低、制备简单、传感与检测可分离的优点,被广泛应用于生化传感检测。研究了对浮栅OECT归一化灵敏度的影响因素。通过对pH、Na^(+)、H_(2)O_(2)进行恒电位测试,系统探究了浮栅OECT的跨导(gm)及次级浮动栅极FG2面积(A_(FG2))对归一化灵敏度的影响。实验结果表明,在一定电压范围内,器件检测灵敏度随器件跨导的增大而增大。此外,A_(FG2)增加时,根据串联电容分压的方式,电容型传感(pH、Na^(+)检测)及电荷转移型传感(H_(2)O_(2)检测)的有机半导体/电解质处有效栅压、跨导均增加,进而导致归一化灵敏度大幅提高。总体而言,增大gm和A_(FG2)均可有效提高检测灵敏度。同时,实现了对pH、Na^(+)、H_(2)O_(2)的高灵敏度检测,pH检测灵敏度最高为0.069/pH,Na^(+)检测灵敏度最高为0.027 dec-1,H_(2)O_(2)检测灵敏度最高为0.33 dec-1,检测灵敏度均高于同类传感器。

Floating gate organic electrochemical transistor(OECT),as a new sensing and detection platform,is widely used in biochemical sensing and detection due to its advantages of low working voltage,simple preparation and separable sensing and detection.The factors influencing the normalized sensitivity of the floating gate OECT were studied.The effects of transconductance(gm)and extended floating gate FG2 area(A_(FG2))of the floating gate OECT on the normalized sensitivity were systematically investigated by constant potential tests of pH,Na^(+)and H_(2)O_(2).The experimental results show that the detection sensitivity of the device increases with the increase of the transconductance of the device within a certain voltage range.In addition,with the increase of A_(FG2),the effective gate voltage and transconductance at the organic semiconductor/electrolyte of capacitive sensing(pH and Na^(+)detection)and charge transfer sensing(H_(2)O_(2)detection)increase according to the voltage dividing method of series capacitors,which leads to a significant increase in normalized sensitivity.In general,increasing gm and A_(FG2)can effectively improve the detection sensitivity.Meanwhile,the high sensitivity detection of pH,Na^(+)and H_(2)O_(2)was realized.The maximum sensitivity of pH detection is 0.069/pH,the maximum sensitivity of Na^(+)detection is 0.027 dec-1,and the maximum sensitivity of H_(2)O_(2)detection is 0.33 dec-1,all the detection sensitivities are higher than those of similar sensors.