Seminaphthorhodafluor Derivatives Bridged Periodic Mesoporous Organosilicas for Detection of Cu2+

Seminaphthorhodafluor (SNARF) Schiff base (SNARF-SB) bridged periodic mesoporous organosilicas (SSPMOs) with “turn-on” fluorescence enhancement for sensing Cu 2+ were synthesized via a template-directed co-condensation method. Small-angle x-ray scattering (SAXS) patterns, high resolution transmission electron microscope (HRTEM) images, and N 2 adsorption–desorption isotherms indicated the presence of mesoporous structure in the SSPMOs. FT-IR spectra and 29 Si MAS NMR data confirmed the successful incorporation of bridged organic groups in the framework of SSPMOs. The luminous properties that SSPMOs had a selective response to Cu 2+ were investigated by UV–Vis absorption spectroscopy and fluorescence spectroscopy. The limit of detection (LOD) was 5.1 × 10 –7  M and binding stoichiometry was determined 1:1 between SNARF-SB and Cu 2+ . The fluorescence enhancement of SSPMOs towards Cu 2+ was induced by ring-opening of the spirolactam in SNARF-SB in framework of SSPMOs, which was confirmed by FT-IR spectra of SNARF-SB with Cu 2+ . Moreover, SSPMOs have improved fluorescence lifetimes compared with that of SNARF-SB. Therefore, SSPMOs can be a progressive chemical sensor for Cu 2+ due to its high selectivity, recyclability, and stability.