Modified graphene based molecular imprinted polymer for electrochemical non-enzymatic cholesterol biosensor

Abstract

This work reports the development of cost effective sensor material prepared from modified graphene oxide based molecular imprinted polymer (GO-MIP). Firstly graphene oxide (GO) prepared from modified Hummers method undergoes acid functionalization to form GOCOOH. It further undergoes surface modification with glycidyl methacrylate (GMA) in presence of N,N′-dicyclohexylcarbodiimide (DCC), dimethylaminopyridine (DMAP) and dimethyl sulfoxide (DMSO) to form GOCHCH2. The obtained GOCHCH2 undergoes molecular imprinting process with methacrylic acid (MAA) as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross–linker, α,α′-azobisisobutyronitrile (AIBN) as the initiator and cholesterol as the template molecule. The different preparatory stages of materials were characterized by FTIR, XRD, Raman and TEM techniques to understand the formation. The obtained GO-MIP used as an active material for cholesterol sensing where the sensor demonstrate a lower limit detection of 0.1nM and response time of ∼2min with maximum sensing performance at pH 5.0. The repeatability of the sensor is checked up to eight cycles and interference of cholesterol with ascorbic acid (AA), uric acid (UA) and glucose were also studied. The material shows a negligible (AA, UA), modest (Glucose) interference and better performance in human blood samples suggesting the real-time usability of the sensor.