PLASMONIC NANOCUBES FOR FLUORESCENCE-BASED SENSING

Abstract

One key figure of merit in evaluating fluorescence-based sensing platforms is amplified signals with a high signal-to-noise ratio. In this study, the potential of gold (Au NCs) and silver (Ag NCs) nanocubes were separately evaluated. The ability to manipulate light-matter interactions is an important aspect for the rational design of fluorescence-based sensing platforms. Using Au NCs to pre-quench RiTC dye followed by aggregation using cysteamine gives up to 200-fold enhancement and a signal beyond free RiTC. The main factors for fluorescence enhancement of spectrally similar dyes with different quantum yields using self-assembled Ag NCs on PDMS substrate were investigated. Namely, the size of assembled Ag NCs, the density of “hot spots” and orientation type were evaluated. We observed that 95nm-AgNCs in the edge-to-edge orientation give the best enhancement for rose bengal. The enhancement for RiTC remains limited, indicating that such platforms benefit low quantum yield dyes more significantly.