A reduced graphene oxide/α-cyclodextrin hybrid for the detection of methionine: electrochemical, fluorometric and computational studies

We report on fluorometric and voltammetric detection of L-methionine (Met) based on host-guest interactions between Met and reduced graphene oxide/alpha-cyclodextrin (rGO/alpha-CD) hybrid materials. For voltammetric measurements, rGO/alpha-CD was used as an electrode modification material and successful detection of Met was achieved. Also, rGO/alpha-CD was used as a fluorescence quencher (turn off) for luminol which was employed as a fluorescent probe. The addition of Met into the same solution gave rise to fluorescence enhancement (turn on) after the host-guest recognition between Met and rGO/alpha-CD which caused the release of luminol. Interactions of luminol and Met with rGO/alpha-CD were modeled by molecular docking using AutoDock Vina and the interaction energies were predicted to be -4.3 and -4.4 kcal mol(-1), respectively. The proposed biosensor is considered to be a promising model for the detection of Met.