Highly Selective and Sensitive Assay for Hydrazine Based on the Plasmonic Response of Cyanurate-Stabilized Silver Nanoparticles

Abstract

We report here a facile, selective, and sensitive approach for the detection of hydrazine (N2H4) based on cyanurate-stabilized silver nanoparticles (cyanurate-Ag NPs) in aqueous solution. In the absence of N2H4, the cyanurate-Ag NPs possess a strong surface plasmon resonance (SPR) at around 418 nm. Significantly, the SPR absorption increased and the peak blue-shifted to 410 nm with a color change from red to bright yellow in the presence of N2H4. These changes can be understood from the oxidative dissolution of Ag NPs by dissolved O2 in solution due to the nucleophilicity of N2H4. The process gives rise to the donation of electron density causing a decrease in the Ag NP size. Meanwhile, the Ag NPs were reproduced by N2H4 for the strong reducing power. Then, the main factors, including reactants concentrations, pH, and incubation time, were specifically investigated. Under the optimal experimental conditions, the relative absorbance is proportional to the logarithm of concentration of N2H4 in the range of 0.01–40 μM with a high selectivity. The detection limit was calculated to be 0.01 μM based on a signal-to-noise of 3. The developed assay is able to take advantage of low cost, fast response, and easy operation. Moreover, this approach also can be potentially useful for selective and sensitive trace N2H4 in water.