Metal-enhanced fluorescence from paper substrates: Modified spectral properties of dyes for potential high-throughput surface analysis and assays and as an anti-counterfeiting technology

In this paper, we report the first observation of metal-enhanced fluorescence emission of fluorophores from paper substrates. The fluorescence intensity is ≈5- and ≈9-fold brighter from Rose Bengal (RB) and Pt(II) octaethylporphine (PtOEP), respectively, on silver colloid-deposited paper as compared to uncoated paper. In addition, a reduced lifetime of RB near to silver particles (0.77 ns) was observed as compared to the non-silvered control sample (0.86 ns). An equivalent photostability of RB on Ag colloid-deposited paper and uncoated paper was also observed. Our findings are potentially helpful in applications to high-throughput surface analysis and as the basis of an anti-counterfeiting technology.