Facile synthesis of polyphenol mediated metal nanocomposites for selective sensing of methylmercury

In this article we report on the synthesis of metal morin nanocomposites. Morin, a naturally occurring polyphenol has been used to generate nickel, copper and nickel-copper bimetallic nanocomposites at room temperature. The method offers advantage of being simple and free from environmental hazards. The synthesized nanocomposites have been characterized thoroughly using various analytical techniques. The materials so obtained were explored for the sensing of methylmercury at pM concentrations. It was found that the morin nanocomposites showed selective optical response towards methylmercury by generating an absorbance peak at lambda(max) 250 nm. Out of the three nanocomposites, Cu- morin nanocomposite was found to be a better candidate as sensor. The linear range of detection was found to be 33 pM-100 pM. Infra red spectroscopic data suggested formation of Hg-C bond as the reason behind such type of sensing. This method was further extended towards detection of methylmercury in the natural samples like, river water and its sediment. The material can be reused with significant efficiency for two successive runs.