Self-assembly of a silver nanoparticles modified electrode and its electrocatalysis on neutral red

Silver nanoparticles (AgNP) were synthesized with NaBH4 as reducing agent and oleate as stabilizer. AgNP and L-cysteine (L-cys) were co-deposited on a gold electrode surface to fabricate the AgNP/L-cys modified electrode (AgNP/L-cys/Au). First, we prepared the L-cysteine self-assembled film modified gold electrode through S-Au bond, then it was rinsed into the Ag colloid solution to prepare the Ag nanoparticles/L-cysteine modified electrode through interaction of the silver surface and the carboxylate and amino groups of L-cysteine. After the self-assembled electrode was prepared, the electrochemical behavior of the modified electrode was investigated. The electrochemical response of neutral red (NR) on the modified electrode was investigated. The electrochemical response of cyclic voltammetry and determination by differential pulse voltammetry of neutral red on the modified electrode were reported. We also observed that the modified electrode catalyzes the redox process of neutral red, which provided another way of applying Ag nanoparticles in composite neutral red-AgNP films.