Construction of dual-mode photochromic fluorescence switching system based on water-soluble rare earth phosphates and carboxyl-containing diarylethene

Abstract

Photochromic fluorescent switches have been attracting great research interest owing to their optical color and fluorescence can be reversibly modulated by light stimulation. An efficient way to construct photochromic fluorescence switching system is to integrate photochromic molecule with an energy level-matching fluorophore by non-covalent assembly. In this paper, we reported the design of a water-soluble photochromic fluorescent switch (OF–CO2H@Ce6Tb4·P) with dual signal changes (optical color change and fluorescence ON/OFF) by combining Ce, Tb co-doped phosphate hybrid (Ce6Tb4·P) and diarylethene containing carboxyl groups (OF–CO2H) via hydrogen bonding. Ce6Tb4·P showed the typical green fluorescence of terbium ions due to the sensitization effect of cerium ions. OF-CO2H can undergo reversible photoisomerization reaction, accompanied by changes in optical color (colorless to pink) and UV–visible absorption. Moreover, controlling the photoisomerization of OF-CO2H can regulates the spectral overlap between its absorption and Ce6Tb4·P emission, thus achieving reversible modulation of the optical color and fluorescence of OF-CO2H@Ce6Tb4·P. The demonstrations of photocontrolled dual-mode signaling in photoswitchable patterning shows that OF-CO2H@Ce6Tb4·P is suited for surface-involved photocontrolled applications such as advanced optical anti-counterfeiting and information storage.