Graphene/Poly(aniline-co-diphenylamine) nanohybrid for ultrasensitive electrochemical glucose sensor

Abstract

In this work, a copolymer (polyaniline(PANI)-copolymer(co)-polydiphenylamine (PDPA)) hybrid impregnated on graphene (Gra) nanosheets was examined. At first, graphene was synthesized by the oxidation of natural graphite employing modified Hummer’s method and subsequently reduced using hydrazine monohydrate. Then, interfacial chemical oxidative polymerization was engaged to synthesize PANI, PDPA, and copolymer (PANI/PDPA) along with graphene nanosheets in liquid–liquid (CHCl3/HCl) interface individually. During the polymerization process, PANI and PDPA chain grown well and dispersed homogeneously on the graphene nanosheets. Morphological and molecular vibrational analyses were confirmed by field emission scanning electron microscopy (FESEM) and Fourier transform infra red spectroscopy (FTIR). In addition, the electrochemically modified Gra-PDPA, Gra-PANI, and Gra-copolymer hybrids show good electrical conductivity ensured via cyclic voltammetry (CV). The enhanced electro-catalytic activity of Gra-PANI-co-PDPA-ME towards glucose with superior sensitivity 0.51 μA/μM at 5 s was achieved. The combined existence and synergistic interaction amid of graphene, aniline and diphenoquinone diamine (DPDI2+) provides enhanced electron transfer for the glucose oxidation. Also, Interference studies ensure that the fabricated sensor is best suitable for glucose sensing performance.