Abstract

We present a pH-sensitive AlGaN/GaN ion sensitive field-effect transistor (ISFET) with monolithically integrated Wheatstone bridge layout and demonstrate the possibility to identify and to compensate the influence of cross-sensitivities to environmental changes, such as temperature, without the need of an external electronic circuit. Based on this Wheatstone-approach low-drift penicillinase-modified AlGaN/GaN solution-gate field-effect transistors (PenFET) with an ultrathin Al2O3 gate coating were prepared and exhibit improved stability and sensitivity compared to PenFETs with conventional wet chemically oxidized gate surface over a course of 60 days as they yield a denser, more homogeneous enzyme layer on the gate area. Moreover, using the Wheatstone-approach can identify a loss of physisorbed enzymes as the dominant aging mechanism for shorter time-periods and stable operation conditions after a period of 10 days with an extracted average Michaelis constants of (20 ± 4) μM for the immobilized enzyme layer by quantitative evaluation applying a kinetic model.By application of the Wheatstone-approach for acetylcholinesterase-modified AlGaN/GaN solution-gate field-effect transistors (AcFET) as a model, we demonstrate that temperature-induced drift can be differentiated from substrate-induced signals and a substantial loss of immobilized enzymes over the course of 12 days after production can be identified.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.