Preparation and study of photoswitchable fluorescence nanoparticles based on spirobenzopyran

The preparation and performance characterization of <50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented. The nanocomposites were fabricated by means of a modified miniemulsion polymerization process, in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix, respectively. The obtained nanocomposites with a high relative fluorescence quantum yield (Q) exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer. The stability of photomerocyanine was also improved.