A glassy carbon electrode modified with poly-nickel hydroxy salen (poly-Ni(OH)salen) film was successfully developed for the electro-oxidation of aldehydes in alkaline media. This film can be prepared in two steps: (i) electropolymerization of N,N -bis-(salicylidene)ethylenediaminonickel(II), or nickel(II) salen, in acetonitrile containing 0.05 M tetramethylammonium tetrafluoroborate (TMABF 4 ), followed by (ii) film transformation in sodium hydroxide solution. Ultraviolet-visible spectrophotometry and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy were employed to confirm the existence of polymeric nickel salen-based films. Cyclic voltammetry results reveal that the poly-Ni(OH)salen film modified electrode can respond to aldehydes, especially acetaldehyde, by giving anodic peak currents related to their electro-oxidation. Parameters affecting the formation and the electrocatalytic performance of the film were optimized. Under the optimum conditions developed herein, the poly-Ni(OH)salen electrode exhibited good linearity over an acetaldehyde concentration range of 0.25 to 20.0 mM with a detection limit of 0.15 ± 0.05 mM. Using the standard addition method, acceptable recovery percentages of acetaldehyde in liquid milk samples were achieved. Additionally, the stability of the modified electrode during the electro-oxidation process is discussed.Organic compounds, including alcohols, phenols, and carbonyl compounds, commonly make up key components or toxic contaminants in food, beverage, and cosmetic products, as well as environmental pollutants generated through biomass or fossil fuel burning. Low-level exposures to these compounds can cause eye, nose, throat, and skin irritation whereas prolonged or concentrated exposures can have carcinogenic effects on humans and animals. 1-3 Therefore, the effective monitoring of these organic compounds has become an important issue. Most organic compounds are analyzed through the use of conventional techniques such as gas chromatography and high performance liquid chromatography. 4-7 Since these techniques require well-trained technicians, are time-consuming, and suffer from the high cost of routine operation, development of simple, rapid, cost-effective, yet highly sensitive techniques for the determination of organic compounds is of much interest. Electrochemical methods of analysis fit these requirements. For instance, voltammetric and chronoamperometric methods can be applied to detect organic compounds via their redox reactions. However, due to the fact that electrochemical detection of organic compounds is frequently limited by either slow electron transfer reactions at conventional electrodes 8 or irreversible passivation of the electrode surfaces, proper electrocatalysts are necessary for the improvement of reaction efficiency.Platinum and other precious transition metals have been considered as suitable electrocatalytic electrodes for numerous electron transfer reactions of organic compounds, e.g., alcohol oxidation, 9-12 phenol oxidation...
