An electrochemical sensor for formaldehyde detection based on a novel organometallic composite

Formaldehyde (CH2O), a carcinogen to humans, is an automotive exhaust gas and an important chemical in the manufacturing of a variety of consumer products [1]. Among various analytical methods for detection of formaldehyde, electrochemical sensors have attracted more attentions because of their high sensitivity, selectivity, easy preparation, fast detection, low consumption and capability [2, 3]. In the present study, a simple and highly sensitive electrochemical method was developed for the determination of formaldehyde through a Ni–Al/layered double hydroxide/Ag nanoparticle composite modified carbon-paste electrode (Ni–Al/LDH/Ag NPs/CPE) as a renewable electrode in 0.1 M phosphate buffer solution (PBS, pH = 7.0). Scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) were performed for the characterization of the Ni–Al/LDH/Ag NP composite. The electrocatalytic activity of the Ni–Al/LDH/Ag NPs/CPE for formaldehyde oxidation was studied by cyclic voltammetry and chronoamperometric methods. The prepared renewable modified electrode as a formaldehyde sensor shows good electrocatalytic activity, fast response time, good stability and reproducibility.