Preparation of Glassy Carbon Electrode Modified with Au Nanoparticles Encapsulated in Dendrimers and Its Application for Determination of Nitrite

KeyWord:dendrimers  chitosan  Au nanoparticles(AuNPs)  electrochemical  nitrite

Abstract:

      A simple and reliable method was developed for the electrochemical determination of nitrite based on glassy carbon electrode(GCE) modified with Au nanoparticles(AuNPs)encapsulated in dendrimers£®Firstly£¬chitosan(Chit) was modified on the GCE£¬and in the presence of coupling agent carbodiimide£¬carboxyl-terminated poly(amidoamine)(generation 4.5) dendrimers were covalently attached onto chitosan through the formation of amide bonds between carboxylic acid groups of the dendrimer and amine groups of chitosan£®The Au(¢ó) ions were coordinated in the interior of dendrimer with nitrogen ligands and then reduced to form AuNPs£¬which was written as Den(AuNPs)/Chit/GC electrode£®The Den(AuNPs)/Chit/GC electrodes were characterized with cyclic voltammetry(CV)£¬electrochemical impedance spectroscopy(EIS)£®The experimental results showed that the present Den(AuNPs)/Chit/GC electrodes have excellent sensitivity for nitrite determination£®The chronoamperometric studies revealed that the amperometric response was rapid and stable£¬and offered a linear dependence over the ranges of nitrite concentrations from 2 ¦Ìmol/L to 20 ¦Ìmol/L and 0.07 mmol/L to 1.12 mmol/L with a limit of detection(S/N=3) down to 1.0 ¦Ìmol/L£®The method was applied in the determination of nitrite in real sample with satisfactory result£®Den(AuNPs)/Chit/GC electrodes are to provide a nanostructured platform for the development of electrochemical sensors and biosensors.