Fluorescence chemosensors based on functionalized SBA-15 for detection of Pb2+ in aqueous media†
A highly ordered mesoporous silica material (SBA-15) functionalized with 5-(4-carboxy-phenylazo)-8-hydroxyquinoline (CPA-8-HQL) for use as a fluorescence chemosensor for Pb2+ detection has been reported in this study. XRD, TEM, FT-IR, UV-vis diffuse reflectance spectra and TGA were used to characterize the grafting process. The results proved that CPA-8-HQL was successfully anchored into the channel of SBA-15 and that the primary ordered mesoporous structure of SBA-15 was well preserved. A fluorescence spectrophotometer was utilized to investigate the sensing properties, and a highly fluorescent enhancement at 429 nm was observed in the presence of Pb2+. Measurements of the sensitivity parameters demonstrated that the obtained organic/inorganic hybrid possessed excellent sensitivity and selectivity to Pb2+ in aqueous media. The lowest limit of detection was 4.90 × 10−7 mol L−1 for Pb2+.