Graphene/graphite/molecularly imprinted polymer nanocomposite as the highly selective gas sensor for nitrobenzene vapor recognition

A novel graphene-based chemiresistor gas sensor was introduced for nitrobenzene vapor detection. A molecularly imprinted polymer (MIP) containing the cavities compatible with nitrobenzene molecules was synthesized using methacrylic acid and vinyl benzene as the functional monomers. The imprinted polymeric particles were mixed with graphene to produce a nanocomposite chemiresistor gas sensor. The presence of graphite alongside graphene in the nanocomposite was found to be necessary to achieve a proper difference between the MIP and non-imprinted polymer (NIP)-based sensors. It was found that the addition of poly(methyl methacrylate) in the nanocomposite composition led to better physical durability, enhanced selectivity and higher resistance against humidity effect. Central composite experimental design was utilized to optimize the sensor influencing parameters. The response of the prepared sensor was reversible and a relative standard error equal to 3.5% was obtained for 3 separate determinations. The sensor showed linear response in the concentration range of 0.50-60.0 ppm. The detection limit was calculated to be 0.2 parts per million (S/N). (C) 2014 Elsevier Ltd. All rights reserved.