Effects of N2 and O2 annealing on the multianalyte biosensing characteristics of CeO2-based electrolyte–insulator–semiconductor structures

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 N2 and O2 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 °C in O2 ambience exhibited a better performance with higher multianalyte sensitivity and a lower drift rate compared with the membrane annealed in N2 ambience. Oxygen in O2 ambience may cause stronger reflow and fill in the oxygen vacancy so that the material properties and sensing capability can be improved in O2 annealing ambience.