Electrochemical non-enzymatic glucose biosensors based on Au-thiol-linked molecular architectures

In this work, an electrochemical non-enzymatic glucose sensor consisting of di-methanethiol-grafted poly (3,4-propylenedioxythiophene), gold nanoparticles (Au NPs), and reduced graphene oxide (rGO) was synthesized by a one-step method through Au-S chemisorption. The structure and morphology of the as-prepared poly (ProDOT-(MeSH)₂)/Au/rGO composite were characterized by fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the composite was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on glassy carbon electrode (GCE). The results show that because of the hydrogen bond interaction between the thiol group on the polymer units and the functional groups on GO, poly (ProDOT-(MeSH)₂)/Au/rGO was successfully prepared. In addition, due to the unique morphological structure of the composite and the ability to absorb glucose molecules through hydrogen bonds, the poly(ProDOT-(MeSH)₂)/Au/rGO electrode possesses excellent selectivity and unique sensitivity (46.13 μA mM⁻¹ cm⁻²) for sensing glucose in the linear range of 0.04–16.0 mM with a detection limit of (S/N = 3) 0.01. This paper demonstrates that the poly(ProDOT-(MeSH)₂)/Au/rGO composite holds great promise for application as a new glucose sensor in life science.