Microwave-assisted covalent modification of graphene nanosheets with hydroxypropyl-beta-cyclodextrin and its electrochemical detection of phenolic organic pollutants

Hydroxypropyl-beta-cyclodextrin (HP-beta-CD) modified graphene nanosheets were successfully prepared using a facile and rapid method assisted by microwave irradiation in water medium, which involves the reaction between the carboxyl groups of graphene oxide (GO) and the hydroxyl groups of HP-beta-CD followed by the reduction of GO into reduced GO (RGO) utilizing hydrazine hydrate. The as-prepared HP-beta-CD-RGO nanocomposites were characterized by Fourier transform infrared spectra, Raman spectra, X-ray photoelectron spectroscopy, thermogravimetric analyses, contact angle measurement, transmission electron microscopy, atomic force microscopy and electrochemical impedance spectroscopy. The new nanocomposites possess unique properties of high surface area and host-guest recognition, thus can be used to enrich and detect inorganic, organic and biological molecules. Cyclic voltammetry measurement (CV) revealed that the HP-beta-CD-RGO modified glassy carbon electrode exhibited outstanding supramolecular recognition and high electrochemical response to several phenolic organic pollutants, and the oxidative peak current decreased linearly with the concentration of Nitrophenol down to a detection limit of 1 x 10(-8) M.