Electroanalytical characteristic of a novel biosensor designed with graphene–polymer-based quaternary and mesoporous nanomaterials

Here, we propose the novel fabrication of graphene–polymer (GP)-based quaternary nanocomposite and mesoporous (MS) nanomaterials sensor [ $$\hbox {NaLa}(\hbox {MoO}_{\mathrm {4}})_{\mathrm {2}}$$ -GO-PPy (NLMG-PPy), CuZnSnSe-GO-PPy (CZSG-PPy) and $$\hbox {In}_{\mathrm {2}}\hbox {O}_{\mathrm {3}}$$ -G- $$\hbox {SiO}_{\mathrm {2}}\,20{\%}$$ (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), energy-dispersive 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 $$1\,\upmu \hbox {l}$$ sample volume within 50 s. Through a low identification point of an individual cell, the MS and GP sensor had an absolute scope of 1–100 CFU per $$\upmu \hbox {l}$$ volume of sample (i.e. $$10^{\mathrm {3}}$$ – $$10^{\mathrm {5}}\,\hbox {CFU ml}^{\mathrm {-1}})$$ . 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.