An Electrochemical Sensor for Hydrazine Based on CoFe2O4 Nanoparticles: Toward Water Samples

Environmental pollution and food safety are currently a focus of considerations worldwide. Hydrazine is a highly carcinogenic substance and may cause water source contamination, owing to its wide-range applications involved with industrial process. For example, hydrazine can function as corrosion inhibitor, antioxidant, catalyst, reducing agent, photographic developer, rocket propellant, and is frequently used as the starting material for the synthesis of insecticides, explosives, dyestuffs and pharmaceuticals. However, it has adverse effect on health such as brain damage, DNA damage, and creation of blood abnormalities and irreversible deterioration of nervous system. Therefore, humans exposed to hydrazine would bear severe health risk. In this regard, detection of this poisonous substance is of practical importance [1]. Electrochemical methods are practical and attractive because electrochemical instrumentation is usually compact, relatively inexpensive, reliable and sensitive. It is known that at a bare electrode surface, the electrochemical oxidation of hydrazine requires high-overpotential. To improve the detection performance, a variety of nanomaterials have attracted worldwide attention, such as carbon materials, metal nanoparticles, and metal oxides [2]. In particular, the magnetic nanoparticles CoFe2O4 have attracted great attention due to large specific surface area, low toxicity, and magnetic properties. Most importantly, it can be easily separated from the aqueous samples by an external magnetic field, and has a good auxiliary catalytic property [3]. In this work, we tried to develop a specific sensor electrode for the determination of phenol by modifying GCE surface using CoFe2O4 nanoparticles and (14E)-4-((E)-4-(2-hydroxybenzylideneamino)benzyl)-N-2- hydroxybenzylidenebenzenamine (see fig. 1). The hydrazine sensor, appeared to exhibit a good 423 linear range of 1×10-6–7.4×10-3 M and a detection limit of (S/N=3) 1.7×10-7 M. The selectivity of the modified electrode for hydrazine was studied for a number of ions such as, Na+, Cl-, Ca+2, Mg+2, and SO4 -2 and biomolecules such as glucose and ascorbic acid. Therefore, modified electrode appears to be a good candidate for the oxidation and quantitative determination of hydrazine. Fig. 1. Chemical structure of (14E)-4-((E)-4-(2-hydroxybenzylideneamino)benzyl)-N-2- hydroxybenzylidenebenzenamine