TOWARD FLUORESCENCE ENHANCEMENT OF DYES IN MESOPOROUS SiO2 AND ORGANIC FILMS

Abstract

Large enhancement of spectroscopic signal is common in Raman spectroscopy on metal surfaces (Surface Enhanced Raman Spectroscopy, SERS).1 However, only a few studies of fluorescence enhancement have been reported on gold surfaces2, 3 and GaP/SiO2 multilayers.4 Photonic band gap multilayers (PBGM) made of quarter wave stacks of alternating SiO2/TiO2 layers were designed at MTSU5 to generate Bloch surface waves (BSWs). The PBGMs were used to observe label-free protein/antibody binding events at the multilayer surface with higher optical sensitivity than for fluorescent dye-labeled proteins and antibodies on glass substrates.6 Here we report the investigation of enhancement of fluorescence through coupling with BSWs in PBGMs. MATLAB simulations showed that BSWs are maximized inside the PBGM top layer.7 Three different materials were characterized for optical response on PBGM: m-SiO2, poly (methyl-methacrylate, PMMA), and AF1600 (Teflon copolymer).