Highly Sensitive Gas Sensor-based on Zn2SnO4 Nanocomposite for Biomarker Detection

Non-Invasive biomarker detection has gained tremendous attention, owing to the recent advancements in gas sensor technology. In this work, Zn2 SnO4, a composite of SnO2 and ZnO has been synthesized using sol-gel method. The synthesized solution has been deposited on the interdigitated gold electrodes. The fabricated sensor demonstrates notable selectivity for ammonia over ethanol, dimethyl sulfide, and acetone. The sensor has shown appreciable % response of 17.21 $\%$ at 500 ppb and $186.47 \%$ at 100 ppm towards ammonia at $180^{\circ} \mathrm{C}$. The deposited nanocomposite exhibits high sensitivity, primarily due to its small crystallite size. Moreover, the sensor has demonstrated fast response and recovery of 9 s and 13 s towards 500 ppb and 100 ppm ammonia. To support the response behavior of fabricated sensor, the sensing mechanism of Zn2 SnO4 towards reducing analyte ammonia has been presented. Furthermore, X-Ray diffraction (XRD) has been done to analyze the crystal structure. Also, surface morphology of the prepared sample has beens studied using Field Emission Scanning Electron Microscopy (FESEM).