The Preparetion Of Graphene-Like Nanocomposite Interfaces And Their Application In Biosensor Fields

It is known that graphene is an excellent material with high conductivity, it plays an important role in the field of electron device, battery electrode material, nanocomposite and biosensor. Recently, the nanocomposite has attracted wide attention by many scientists. The graphene-like has a wide application in electrochemical sensor and electrocatalysis. Among the methods to fabricate nanocomposites, electrochemical method attracts much attention due to its fast, green and easily controlled process. In the process, different nanocomposites can be obtained by changing experimental parameters.Different graphene-like nanocomposites can be prepared by electrochemical method, including PXa-ERGNO, GZNWs and MoS2-ZnO, and a series of investigations were carried out based on these nanocomposites. The jobs are as follows:(1) In this paper, the poly(xanthurenic acid, Xa)-reduced graphene oxide (PXa-ERGNO) interface, which owns rich negative charged active sites and accelerated electron transfer ability, was fabricated for monitoring the positively charged guanine and adenine. Scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectra, X-ray photoelectron spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry were adopted to characterize the morphology and prove electrochemical properties of the prepared interface, respectively. The PXa-ERGNO interface exhibited prominent synergistic effect and good electrocatalytic activity to sensitively determine guanine, adenine and chloramphenicol compared with sole PXa or ERGNO modified electrode. And the nanocomposite can act as an excellent electrocatalyst for guanine, adenine and chloramphenicol.(2) Graphene oxide (GNO) was used as the supporting material for constructing a series of synchronously electrochemically reduced graphene oxide and zinc oxide composites (GZNWs). The control of morphology or size of nanostructures is a prerequisite for the nanostructure for fabricating various types of nanocomposites, then changing the electrochemical properties. The experimental parameters, such as the electrodeposition potential, time, and concentration of electrolyte, would influence the composite morphology. Then we compared their morphology-dependent electrochemical sensing behaviors. The result showed us that different nanocomposite could bring different electrochemical sensing and catalysis ability.(3) The MoS2-ZnO nanocomposite was fabricated by pulsed electrodeposition, and many experimental parameters were investigated during the electrodeposition process, such as the electrodeposition potential, time, concentration of electrolyte and MoS2. The morphologies and electrochemical properties of the prepared MoS2-ZnO nanocomposite were characterized by scanning electron microscopy and differential pulse voltammetry. Among the prepared conditions, MoS2-ZnO nanocomposite, obtained from the conditions of +0.9 V oxidation potential,-1.1 V reduction potential, 900 s electrodeposition time,0.15 M Zn(NO3)2 electrolyte and 2 g/L MoS2-ZnO, presented an optimal ability for DNA detection (MB as the electrochemical probe). It had reached the aim of improving the sensitivity of their detection.