Na-cholate micelle mediated synthesis of polypyrrole nanoribbons for ethanol sensing

The low-level sensing of ethanol has gained enormous importance due to its application in human health monitoring, road safety, fermentation and food industries. In this investigation, we report the synthesis of ribbonlike nanostructures of polypyrrole (PPY), a conducting polymer, using sodium cholate micelles as a soft template. The PPY nanoribbons were found to exhibit good sensor response along with high degree of selectivity to ethanol vapour as opposed to several common volatile organic compounds (VOCs) showing its suitability as a selective sensing layer to detect ethanol from a mixture containing ethanol, methanol, 2-propanol, toluene, n-hexane, and humidity. The sensing mechanism and its selectivity to ethanol vapor were explained by considering a hydrogen bond type interaction of the -OH groups of ethanol molecules with large number of =N or -NH groups of the PPY available on the surface due to its nanoribbon morphology. Investigation of the cytotoxicity of the PPY nanoribbons revealed good biocompatibility.