The Nano Gold/silk-febrion Composite Materials Modified Electrodes And Its Application To The Detection Of Environmental Trace Organics

Due to the unique character of nanoparticles such as optical, electrical and catalytic character, nanoparticles have attracted much attention of many chemists for their novel application in modified electrode. In this paper, nanoparticles modified electrode has been fabricated by combining nanotechnique with electrochemical method. Besides, nanoparticles modified electrode fabricated by us is taken into the study on environmental pollution. Such as p-benzenediol and H₂O₂.First,we prepared gold nano-particles colloidal sol by the reduction of HAuCl4 with silk fibroin, and took the colloidal sol into the preparation and optics research..Nano-Au/silk-fibroin colloids were prepared by situ reduction HAuCl4 with silk-fibroin. UV-Vis absorption, fluorescence spectra and resonance scattering spectra have been used to study the structure and characterization of the nanocolloids. It was showed that the Au nanoparticles were uniformly embedded in silk-fibroin colloid, which resulted in enhancement of the strength of fluorescence spectra and resonance scattering spectra of silk-febroin.The prepared colloids owed good dispersity and stability,so it can be kept for a long period.Second,gold electrode modified with gold nano-particles was employed for electrocatalytic oxidation of p-benzenediol.Several factors affected the electrocatalytic oxidation were investigated,such as acidity and scan rate.The modified electrode has good electrocatalysis to p-benzenediol in acid.In 0.25mol/L phosphate buffer solution(pH=3.55),when differential pulse voltammetric method was used,there was an exerllent linearity between oxidation current and concentration of p-benzenediol in the range of 4×10- 6～1×10-3 mol/L with a detection limit of 1.5×10-7mol/L.The results revealed that the modified electrode could be used to the determination of p-benzenediol in imitative waste water samples with good result.Third,the modified electrode with gold nano-particles/@silk-fibroin immobilized on glassy carbon electrode was employed for electrocatalytic oxidation of cytochrome c. The affection of acidity and scan rate were investigated, and the electrocatalytic oxidation mechanism of cytochrome c at modified electrode was studied. The results show that gold nano -particles immobiled silk further the direct electron transfer of cytochrome c.Fourth,horseradish peroxidase and gold nano-particles was immobilized on the surface of the glassy carbon electrode can undergoing effective Direct Electrochemistry. The results show that gold nano-particles/silk fibroin immobiled further the direct electron transfer of Horseradish Peroxidase .The result also showed that the immobiled HRP retained its bioelectrocatalytic activity for the reduction of H2O2 and can quickly respond to the change of the concentration of H₂O₂.The mothod of the preparation of biosensor in this text can easily be manipulated,it can be used to acquire the direct electrochemistry of other enzymes or protein and bio-fuel cells,and it can also be used to determine environmental trace pollution.So it probablys owe a good application in the future.