Multimodal Assay of Arsenite Contamination in Environmental Samples with Improved Sensitivity through Stimuli-Response of Multiligands Modified Silver Nanoparticles

Arsenic has an open circulatory system in nature and is highly toxic to both humans and the ecosystem. This study describes a multimodal assay of arsenite (As(III)) in environmental samples via stimuli-response of multiligands functionalized silver nanoparticles (Ag NPs). The multiligands functionalized Ag NPs are prepared through chemical reduction using asparagine (Asn) as the capping ligand and further modification with reduced glutathione (GSH) and dithiothreitol (DTT). The obtained GSH/DTT/Asn-Ag NPs can be used as multifunctional probes for the multimodal assay of As(III) owing to the excellent plasmonic property and unique electrochemical activity. The multimodal method can detect As(III) not only by naked-eye colorimetric and spectrophotometric assay but also by turn-on and highly sensitive electrochemical assay. The strategy features convenient operation, short analytical time, on-site assay, high sensitivity, and low cost. The As(III)-responsive multimodal sensor demonstrates excellent performance for detection of low trace As(III) in various environmental water and juice samples. The results are in accordance with the ones obtained by the inductively coupled plasma mass spectrometry (ICP-MS) method. Besides, the plasmonic metal nanoparticles-based multimodal sensing method can be used to ameliorate the analytical performance of sensors for toxic targets, which will be very conducive to facilitate the practical application of sensors related to environmental and food monitoring.