Thirty Years of CHEMFETs – A Personal View

Nitrate ion detection using AlGaN/GaN heterostructure-based devices without a reference electrode

“…Unfortunately such devices typically require a reference electrode in order to bias the gate of the transistor beyond the threshold voltage, to allow majority carriers to travel through the conductive channel [4]. On-chip miniaturised Ag/AgCl reference electrodes have been designed and tested, but their fabrication is typically complex and electrode solution leakage remains a serious issue compromising sensor accuracy and device lifetime [5].…”

Synchrotron-based XPS studies of AlGaN and GaN surface chemistry and its relationship to ion sensor behaviour

“…This pioneering work enabled the miniaturisation of ion sensors; however, silicon-based sensing devices have several major drawbacks related to the gate dielectric; these include charging and chemical instability upon exposure to aqueous solutions [2][3][4]. Furthermore, a reference-electrode is required for biasing purposes and limits sensor stability/lifetime and sensor miniaturisation [1,2,5]. III-Nitride materials are now being considered as promising alternatives for the reliable operation of chemical and biological sensors particularly in harsh environments [6].…”

Complementary Metal Oxide Semiconductor-Compatible Silicon Nanowire Biofield-Effect Transistors as Affinity Biosensors

“…An important requirement of the Ref-GE is that it must maintain a constant potential throughout, which is insensitive to any changes occurring in the electrolyte solution [88]. Any change in V T or I ds can then be assumed to originate from the variation of the inter facial potential at the Si surface.…”