Enhancement of fluorescence from one- and two-photon absorption of hemicyanine dyes by confinement in silicalite-1 nanochannels

We prepared unique organic inorganic composite possessing strong one- and two-photon florescence properties by encapsulating hemicyanine molecules in nanosized silicalite-1 zeolite. The free hemicyanine dye in solvent and confined hemicyanine dye in nanochannels of silicalite-1 showed identical optical one- and two-photon absorption coefficients. By contrast, the fluorescence quantum yields of confined hemicyanine molecules in silicalite-1 channels from one and two-photon absorption were 5 and 3.3-fold, respectively, higher than those of free hemicyanine solution. Such contrasting behaviors in fluorescence were attributed to the isolation and confinement of hemicyanine in nanochannels of silicalite-1. This study represents a promising new strategy in the development of one- and two-photon fluorescence materials and a novel direction for zeolite research and its application in the development of optical materials. (C) 2017 Elsevier Inc. All rights reserved.