Effects of N-2 and O-2 annealing on the multianalyte biosensing characteristics of CeO2-based electrolyte-insulator-semiconductor structures

Abstract

A CeO2-based multi-analyte electrolyte-insulator-semiconductor (EIS) biosensor has been fabricated on silicon substrate. To enhance the material quality and sensing performance, annealing treatment in N-2 and O-2 ambient has been incorporated. To examine the annealing effects, material analyses were conducted using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) to identify optimal treatment conditions. Furthermore, sensing performance for various ions of Na+, K+, urea, and glucose has also been tested. Results indicate that the membrane annealed at 800 degrees C in O-2 ambience exhibited a better performance with higher multianalyte sensitivity and a lower drift rate compared with the membrane annealed in N-2 ambience. Oxygen in O-2 ambience may cause stronger reflow and fill in the oxygen vacancy so that the material properties and sensing capability can be improved in O-2 annealing ambience. (C) 2014 Elsevier B.V. All rights reserved.