Carbon Nanotube-Pt Nanoparticle and Nickel(II) Complex‐Modified Carbon Paste Electrode: A New Sensor for Formaldehyde Determination

Abstract

In this paper, a novel electrochemical electrode for formaldehyde (HCHO) determination based on its electrocatalytic oxidation on carbon nanotube (CNT)-Pt nanoparticle (PtNPs)- bis[5-((4-ndodecyloxyphenyl)azo)-N-(4-noctoxyphenyl) salicylaldiminato]nickel(II) (Ni-DOS)‐ carbon paste electrode (CPE) is reported. The synthesized CNT/PtNPs was characterized by scanning electronic microscopy (SEM) and energy-dispersive X-ray (EDS) spectroscopy. The mechanism of electrocatalytic oxidation and quantification of HCHO were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The results indicated that Ni-DOS/CNT/PtNPs/CPE exhibited good electrocatalytic activity toward HCHO oxidation owing to its high conductivity and large surface area. The effects of some parameters such as different scan rates, pH, and HCHO concentrations were also examined to provide catalysis mechanism for HCHO oxidation at the surface of modified electrode. The proposed electrode demonstrated remarkable electroactivity for HCHO oxidation with long term stability and good reproducibility. The assay achieved a detection limit of a 250 nM and a linear response extending up to 50 µM HCHO concentrations.