Flower-like gold nanoparticles linked to gold DVD platform via L-cysteine self-assembly monolayer: A novel voltammetric sensor for detection ofhydrazine

Hydrazine is a well-known carcinogenic substance with a high reducing property. It is a generalpurpose chemical with wide-range applications in various industries, fuel cells, corrosioninhibiting and etc. The toxic nature of hydrazine as well as its high solubility in water raises the concerns about environmental pollution [1-3]. Therefore, development of simple, fast, accurate and sensitive sensors for monitoring of hydrazine in water, industrial, environmental andbiological samples is of crucial importance today. Here, a novel disposable electrochemical sensor for detection of hydrazine is introduced based on gold nanoparticles (AuNPs) covered on a self-assembly monolayer of L-cysteine (SAM) over a gold digital versatile disc platform(DVD). The characteristics and morphology of AuNPs was characterized by UV-Vis spectroscopy, scanning electron microscopy and atomic force microscopy. Electrochemicalimpedance spectroscopy experiments in a ferri/ferrocyanide solution proved that AuNPs reallyact as an efficient electrocatalyst. Electrochemical behaviour of hydrazine on the AuNPs@SAM@DVD electrochemical sensor was investigated using cyclic voltammetryrevealing the efficient electrocatalytic function of the sensor. This was confirmed by the decreased oxidation overpotentials and increased peak current response of the hydrazine. The quantitative measurements were carried out by differential pulse voltammetry after thoroughoptimization of influential operating conditions such as the amount of AuNPs and the pH and the concentration of supporting electrolyte. At last, the analytical performance of the sensor was demonstrated by determination of hydrazine in several environmental samples. The cheap disposable DVD platforms used as a replacement of expensive gold electrodes removes the concerns about the memory effects and tedious solid surface polishing.

Keywords:

Hydrazine , Gold Naopraticles , Self-assembly monolayer , L-cysteine , DVD , Electrochemical sensor