Thomas Mathew S, White Scott P, Dorfman Kevin D, Frisbie C Daniel
Department of Chemical Engineering and Materials Science , University of Minnesota , 421 Washington Ave. SE , Minneapolis , Minnesota 55455 , United States.
J Phys Chem Lett. 2018 Mar 15;9(6):1335-1339. doi: 10.1021/acs.jpclett.8b00285. Epub 2018 Mar 6.
The floating gate, electrolyte-gated transistor (FGT) is a chemical sensing device utilizing a floating gate electrode to physically separate and electronically couple the active sensing area with the transistor. The FGT platform has yielded promising results for the detection of DNA and proteins, but questions remain regarding its fundamental operating mechanism. Using carboxylic acid-terminated self-assembled monolayers (SAMs) exposed to solutions of different pH, we create a charged surface and hence characterize the role that interfacial charge concentration plays relative to capacitance changes. The results agree with theoretical predictions from conventional double-layer theory, rationalizing nonlinear responses obtained at high analyte concentrations in previous work using the FGT architecture. Our study elucidates an important effect in the sensing mechanism of FGTs, expanding opportunities for the rational optimization of these devices for chemical and biochemical detection.
浮栅电解质门控晶体管（FGT）是一种化学传感装置，它利用浮栅电极将有源传感区域与晶体管进行物理隔离并实现电耦合。FGT平台在DNA和蛋白质检测方面已取得了有前景的结果，但关于其基本运行机制仍存在疑问。通过将羧酸端基自组装单分子层（SAMs）暴露于不同pH值的溶液中，我们创建了一个带电表面，从而表征了界面电荷浓度相对于电容变化所起的作用。结果与传统双层理论的理论预测相符，解释了先前使用FGT架构在高分析物浓度下获得的非线性响应。我们的研究阐明了FGT传感机制中的一个重要效应，为合理优化这些用于化学和生化检测的装置拓展了机会。
