Design of Fluorescence-Enhanced Silver Nanoisland Chips for High-Throughput and Rapid Arsenite Assay

High-throughput and rapid arsenite (As­(III)) monitoring is an urgent task to deal with the critical threat from As­(III) contamination in the environment. In this study, an effective, portable, and sensitive As­(III) assay was developed using the plasmonic silver (pAg) chips for As­(III) detection. The pAg chips were fabricated by a simple seed-mediated method to grow the silver nanoisland films (Ag-NIFs) with the compact nanoislands and adjustable interisland gaps on the large-sized substrates. With appropriate surface functionalization and optimal chip manufacturing, Cy7.5 fluorescence dye can be immobilized on the surface of Ag-NIFs in the presence of As­(III) to output the enhanced fluorescence signals up to 10-fold and improve the detection limit of As­(III) less than 10 ppb. According to our results, the high-throughput detection measurements and wide dynamic range over 4 orders of magnitude implied the broad prospects of pAg chips in fluorescence-enhanced assays. The proposed As­(III) assay has shown great opportunities for the practical application of ultratrace As­(III) monitoring.