Poly(styrene sulfonate) and Pt bifunctionalized graphene nanosheets as an artificial enzyme to construct a colorimetric chemosensor for highly sensitive glucose detection

In this work, we developed a highly sensitive and simple colorimetric method for glucose detection using poly( styrene sulfonate)/Pt-modified graphene nanosheets (PSS-GN-Pt) as peroxidase mimetics. First, in the presence of glucose, H2O2 was generated as the main by-product of glucose oxidase (GOx)-catalyzed reaction. Then, the obtained H2O2 triggered the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to generate blue color with the aid of PSS-GN-Pt nanocomposites as peroxidase mimetics. Via this method, as low as 9.28 x 10(-8) M glucose could be detected with a linear range from 2 x 10(-7) M to 1 x 10(-3) M. Besides absorbency measuring, the visual detection of glucose by naked eyes could also be realized very easily through the observable color changing from colorless to blue. In addition, this strategy was further used to determine the concentrations of glucose both in injection and serum samples with satisfying results. This proposed nanosystem holds great potential for diabetes mellitus research and can be easily expanded to the detection of various H2O2-involved analytes. (C) 2016 Elsevier B.V. All rights reserved.