Polymer membrane stabilized gold nanostructures modified electrode and its application in nitric oxide detection

Abstract

Nafion polymer/gold nanostructures film that can be utilized as a proficient electrochemical sensor for nitric oxide was prepared by an electrochemical process, forming the gold nanostructures (Au_nano) through infiltration into a Nafion (Nf) matrix preassembled on an electrode. The formation of gold nanostructures was monitored by the in situ spectroelectrochemical method. The in situ absorption spectra of Au_nano showed systematic and uniform formation of gold nanostructures at the Nafion (Nf-Au_nano)-modified electrode. The electrochemically formed Nf-Au_nano was characterized by UV-visible spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope, and electrochemical techniques. The surface plasmon absorption spectra recorded for the wet and dry Nf-Au_nano composite film showed the interaction between the gold nanostructures and the swelled polymer matrix. The longitudinal surface plasmon band and the TEM images observed for the Nf-Au_nano showed the formation of nanorod-like and Y-shaped gold nanostructures in the Nafion matrix. In addition to the nanoparticles, the edge-to-edge interactions lead to the formation of 1D assembly. The electrical communication between the gold nanostructures embedded in the Nafion film improved the electrocatalytic properties of the modified electrode toward NO detection. The Nf-Au_nano electrode showed excellent sensitivity for NO detection with the experimental detection limit of 1 nM. The present Nf-Au_nano electrode is very simple to fabricate and is stable, sensitive, and reproducible.