Study of Ag doped SnO2 film and its response towards aromatic compounds present in tea

The work presented here focuses on the synthesis of Ag doped SnO 2 based metal oxide semiconductor gas sensor using co-precipitation method and its performance evaluation towards some vital compounds responsible for the appealing aroma in tea. The sensor is tested to evaluate its response towards four noteworthy compounds (linalool, geraniol, methyl salicylate and trans-2-hexenal) present in the aroma matrix of black tea under diverse working temperature conditions. The prepared Ag doped SnO 2 gas sensor exhibits improved sensitivity at a comparatively lesser working temperature (150°C) than the undoped SnO 2 gas sensor. The proposed Ag doped sensor yields the highest sensitivity towards methyl salicylate(64.69%), an organic ester naturally synthesized by tea plants and is found in green, oolong and black tea. The physical characterization of the sensing material is carried out using XRD(x-ray diffraction), EDS(Energy dispersive X-ray spectroscopy) and SEM (scanning electron microscope). This research will aid in selecting an appropriate sensing material for detection of methyl salicylate which could help in the quality determination of tea.