Gas sensor array assisted with UV illumination for discriminating several analytes at room temperature

Abstract

In this work, a metal-oxide gas sensor array was fabricated for discriminating several gases at room temperature using ultraviolet (UV) illumination. The sensor array consisted of four interdigitated gold microelectrodes, and titanium dioxide (TiO2) nanofibres were electrospun on them. The nanofibres were calcined at 550°C for 1 h. Finally, one of these sensors was coated with a thin layer of gold (Au) using DC sputtering method at a thickness of 2 nm. Similarly, the other two sensors were coated with a thin layer of platinum (Pt) and copper (Cu), respectively, and the last one remained uncoated. The nanofibres were characterised by scanning electron microscope, X-ray diffraction, and UV spectroscopy. The examined analytes were methanol, ethanol, NH3, and acetone, each at seven various concentration levels, including 50, 100, 150, 200, 300, 400, and 500 ppm. Principal component analysis and linear discriminant analysis were used to evaluate the proposed technique. The results demonstrated that the sensor array along with UV illumination could successfully discriminate the analytes at room temperature.‏