Influence of NH3 plasma and Ti doping on pH-sensitive CeO2 electrolyte-insulator-semiconductor biosensors

Abstract

Abstract In this study, CeO2 pH-sensitive sensing membranes in electrolyte-insulator-semiconductor structures on silicon substrate were fabricated. To enhance sensing performance, the membrane underwent Ti doping and NH3 plasma treatment on the surface. To examine the effects of Ti doping and plasma treatment, multiple material properties evaluations were conducted using field-emission scanning electron microscopy, X-ray diffraction, atomic force microscopy, and secondary ion mass spectroscopy. Results indicate that Ti doping and plasma treatment can remove defects and enhance crystallization, thereby achieving improved pH-sensing performance of the membrane with high sensitivity, high linearity, low hysteresis voltage and low drift voltage. CeO2-based EIS membranes with Ti doping and NH3 plasma treatment show promise for future portable pH-sensitive biosensors.