Abstract
Here, we describe a simple approach for the efficient immobilization of poly-L-lysine (PLL) impregnated glucose oxidase (GO(x)) at a manganese dioxide (MnO2)-decorated chemically reduced graphene oxide (CRGO) composite film modified electrode. The MnO2/CRGO film was analyzed by various techniques such as scanning electron microscopy, UVvisible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. MnO2 particles are uniformly deposited at the CRGO surface through an easily adoptable electropolymerization method. The as-prepared (GO(x)-PLL/MnO2/CRGO) composite film exhibited a surface coverage concentration (G) of 2.68 x 1010 mol/cm(2), indicative of high GO(x) loading. The heterogeneous rate constant for the redox reaction of GO(x) has been calculated to be 4.92 s(1). A glucose biosensor was fabricated which exhibits a wide linear range from 0.04 to 10 mM with a limit of detection of 0.02 mM (S/N = 3). The proposed inexpensive, simple, and sensitive sensing approach based on the MnO2/CRGO nanocomposite electrode can be a promising method for the determination of glucose present in the clinical and environmental food analysis.