Electrolyte-gated field Effect Transistors Based on Cu Interdigitated Electrode for H₂O₂ and Glucose Sensing

Abstract

A copper interdigitated electrode was patterned on a piece of printed circuit board. A layer of CNRG-CS composite prepared using graphitic carbon nitride, reduced graphene oxide and chitosan was immobilized on Cu interdigitated electrode as semiconductive channel. Then, the prepared CNRG-CS modified Cu interdigitated electrode was positioned into a home-made chamber to assemble an electrolyte-gated field effect transistor (EGFET)-based sensor for the non-enzymatic detection of H2O2. Also, glucose oxidase (GOx) was immobilized on CNRG-CS modified Cu interdigitated electrode to prepare CNRG-CS/GOx modified Cu interdigitated electrode and to assemble an EGFET-based biosensor for the enzymatic detection of glucose. Two linear dynamic ranges of 0.16-8.0 μM and 8.0-160 μM were obtained for H2O2 detection. Also, two linear dynamic ranges of 0.15-3.5 μM and 3.5-80 μM were obtained for glucose detection. The detection limits (S/N=3) for H2O2 and glucose were 0.12 and 0.14 μM, respectively. The relative standard deviations for repetitive measurements (n=3) of H2O2 (3.0 μM) and glucose (3.0 μM) were 1.8 and 2.5%, respectively. The fabrication reproducibility for five EGFET-based sensors and biosensors prepared and used in different days were 7.4 and 8.2%, respectively.