Enhancing pH Sensors Performance of ZnO Nanorods With Au Nanoparticles Adsorption

Abstract

In this work, the sensing membrane of extended-gate field-effect-transistor (EG-FET) sensor with zinc oxide (ZnO) nanorods (NRs) and Au adsorbed on ZnO NRs were fabricated by hydrothermal method and DC magnetron sputtering. The Pt sheet as a reference electrode, put in sensing membrane and reference electrode to defferent pH valuse buffer solution for linearity and sensitivity analysis. Results showed the both of the ZnO based EG-FET pH sensors exhibited high linearity and sensitivity, and Au-adsorbed exhibited significantly improved sensing performance, the average voltage sensitivity and average current sensitivity of the ZnO NRs based EG-FET sensor was 24.67 mV/pH and <inline-formula> <tex-math notation= LaTeX >$21.4~\\mu \\text{A}$ </tex-math></inline-formula>/pH, and linearity was 0.986 and 0.994, whereas that of the Au-adsorbed ZnO NRs based EG-FET pH sensor was 76.75 mV/pH and <inline-formula> <tex-math notation= LaTeX >$45.66~\\mu \\text{A}$ </tex-math></inline-formula>/pH with a linearity of 0.990 and 0.980.