Electrochemical determination of formaldehyde via reduced AuNPs@PPy composites modified electrode

Abstract

Formaldehyde is a poison around us. We described an electrochemical sensor based on polypyrrole(PPy)-reduced gold for the sensitivity detection of formaldehyde. The pyrrole was modified on glassy carbon electrode by potentiostatic method to obtain PPy/GCE. The gold nanoparticles (AuNPs) were decorated to the PPy/GCE after the treatment of the polypyrrole by overpotential. Thus, a AuNPs-polypyrrole composite modified glassy carbon electrode (AuNPs /PPy/GCE) was obtained. The material was characterized by SEM, EDX and XPS. The optimization of modification conditions for polypyrrole and AuNPs was determined. The PPy/GCE modified by AuNPs has high conductivity and excellent catalytic activity because of its large current response. The formaldehyde detection sensor based on AuNPs /PPy/GCE was established, and the quantitative determination of formaldehyde was carried out by differential pulse voltammetry(DPV). The electrochemical sensor has high selectivity, reproducibility and stability for formaldehyde detection. The sensor can be used to detect formaldehyde in pure water with detection line of 20 μM. The sensor can also be used to detect formaldehyde in milk with detection line of 0.4 mM.