Preparation And Application Of Silver Nanoparticles Modified Electrode

The chemically modified electrode (CME) have been a most burgeoning and one of the most flourish research realms in the electrochemistry and electroannalytic chemistry since it was developed in the 1970th; The study of nanoparticles of noble metals applied in chemically modified electrode has aroused much attention because of their intriguing prospects for the development of novel electrochemical device, electro optical applications and catalysis. In this paper, the silver nanoparticles modified electrode was prepared by combined nano technique with electrochemistry and applied in some field .First, a kind of silver nanoparticles stabilized by oleate was synthesized and characterized by transmission electron microscopy (TEM) and spectrum, some optic properties (such as UV-visible spectroscopy , resonance light scattering and fluorescence ) and electrochemical properties were studied. The results of experiments show that the Ag nanoparticles have very high electrochemical activities, adsorptive characters and electro catalysis to L- cysteine, which provided theoretic foundation and a new possible approach that applied silver nanoparticles into electroannalytic chemistry.Second, a new method for the determination of proteins has been developed based on the enhancement of resonance light scattering (RLS) of Ag nanoparticles in the present of proteins, and the mechanism was discussed. The enhancement of RLS was proportional to the concentration of the proteins and the detection limits were 1.3 ng mL-1 for BSA, 10 ng mL-1 for HSA and 5.7 ng mL-1 for γ-IgG. This method has been applied to the analysis of real human serum samples with satisfied results, indicating that the method present is simple, convenient and sensitive.At last, adsorbent and covalent Ag nanoparticles modified electrodes were prepared by adsorbent and covalent method, respectively. The electrochemical behaviours of SCN-, brilliant cresyl blue (BCB) and nicotinamide adenine dinucleotide (NADH) on modified electrode were studied by Cyclic voltammetry, differential pulse voltammograms and electrochemical impedance spectroscopy. The results of experiments show that the adsorbent modified can be used to the determination of SCN- with the determination limit of 4×10-8mol/L, which has been applied to the determination of Saliva with satisfied results. The covalent Ag nanoparticles modified electrodes can catalyze the redox of BCB and the peak current of BCB is in linear relationship with its concentration; the electrocatalysis of NADH was also investigated primarily.