Functionalized Graphene Obtained via Thiol-Ene Click Reactions as an Efficient Electrochemical Sensor

Functionalized graphene was synthesized via thiol-click reactions, and then a simple approach was adopted to immobilize Au nanoparticles (AuNPs) on the surface of functionalized graphene sheets. This approach is to use cysteamine linker with reactive amine and thiol functional groups at each end. Firstly, cysteamine hydrochloride (HS-(CH2)(2)-NH2 center dot HCl) was incorporated onto the surface of graphene reacted with the C=C bonds by using 2,2-azobis(2-methylpropionitrile) (AIBN) as thermal catalyst. Then, uniform and monodispersed AuNPs were anchored on functionalized graphene surface through electrostatic interaction under acidic conditions. The obtained functionalized graphene/AuNPs composites exhibited excellent electrochemical properties investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The composites electrode exhibited high stability and good selectivity for UA and FA with the detection limit of 0.08 mu M and 0.035 mu M (S/N = 3), respectively. Our work provides a simple, convenient and green route to synthesize functional graphene which is potentially useful in electroanalysis.