Intensity modulation of UV light in gas sensor array to discriminate several analytes at room temperature

In this study, a gas sensor array along with intensity modulation of UV light was utilized to discriminate several gases at room temperature. The sensor array was consisted of two interdigitated microelectrodes and TiO₂ nanofibres were electrospun on them and calcined at 540°C for 90 min. One of these sensors was coated by 2-nm Pt using the DC sputtering method and the other one remained uncoated. In each experiment, the sensor array was located at a distance of 30 mm from a 365-nm UV LED. For intensity modulation of UV light, a staircase waveform voltage was applied to the UV LED. The voltage was included of three voltage steps and the measured powers at a distance of 30 mm from the UV-LED were about 450, 560, and 680 µW/cm², respectively. Analytes including acetone, ethanol, methanol, 2-propanol, and carbon monoxide (CO) at various concentrations ranging from 50 to 500 ppm were examined. Three-dimensional Principal Component Analysis mapping was successfully used for the segregation of all examined gases. The examinations revealed that using sensor array along with intensity modulation of UV light is an effective method for discrimination of several analytes at room temperature.