▎ 摘　　要

Here, we propose the novel fabrication of graphene-polymer (GP)-based quaternary nanocomposite and mesoporous (MS) nanomaterials sensor [NaLa(MoO4)2-GO-PPy (NLMG-PPy), CuZnSnSe-GO-PPy (CZSG-PPy) and In2O3-G-SiO2 20% (IGS20)] to address ignored challenges for Escherichia coli bacteria recognition in polluted samples. Synthesized samples were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energydispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). The sensor could recognize an individual E. coli cell in 1 mu l sample volume within 50 s. Through a low identification point of an individual cell, theMS and GP sensor had an absolute scope of 1-100 CFU per mu l volume of sample (i.e. 103-105 CFU ml-1). The high thickness of negative charge on the surface of E. coli cells actively regulates the concentration of dominant part charge carriers in the mesoporous and G-polymer monolayer, permitting an ongoing check of E. coli concentration in a known sample. Our biosensor is simple and low-cost with great selectivity and fast identification was effectively shown for E. coli detection.