A single hybrid optical sensor based on nanoporous silica type SBA-15 for detection of Pb2+ and I- in aqueous media

A novel organic-inorganic hybrid optical sensor (HQS-SBA-15) was prepared by a two-step post synthesis of SBA-15: functionalization with 3-(iodopropyl)-trimethoxysilane followed by the covalent attachment of 8-hydroxyquinoline-5-sulfonic acid. XRD, N-2 adsorption-desorption, TEM and FT-IR were used for the characterization of the prepared materials. A fluorescence study showed that the suspension of HQS-SBA-15 in water was able to detect selectively and sensitively two ions with opposite charges, i.e. Pb2+ in the presence of different cations, including Na+, Mg2+, Al3+, K+, Ca2+, Mn2+, Co2+, Cu2+, Zn2+, Cd2+ and Hg+, as well as I- among different anions, including NO2-, NO3-, CN-, Cl-, F-, Br-, CO32-, SO42-, HCO3-, and H2PO4-. The effects of pH, its applicability in real samples and reversibility are also discussed.