Self-assembled dipeptide-graphene nanostructures onto an electrode surface for highly sensitive amperometric hydrogen peroxide biosensors

Self-assembled nanowires of diphenylalanine and graphene (FF-G) nanocomposites have been prepared in aqueous solution by a simple one-step method. Hemoglobin (Hb) as a model molecule is further immobilized on the FF-G nanocomposites in order to construct a H2O2 amperometric biosensor. According to UV-vis spectroscopy, the immobilized Hb, overall retains its original structure and the bioactivity. Systematic electrochemical tests demonstrate that the Hb/FF-G modified glassy carbon electrode shows high electrocatalytic activity to H2O2. The biosensor exhibits a wide linear response in the range from 5.0 x 10(-7) to 5.0 x 10(-4) mol L-1, with a low detection limit of 1.0 x 10(-7) mol L-1. Our results indicate that the nanowires of FF-G nanocomposites obtained in a facile method are promising for application in electrochemical biosensors due to its excellent biocompatibility and good charge -transfer ability. (C) 2017 Elsevier B.V. All rights reserved.