Highly selective fluorescence chemosensors based on functionalized SBA-15 for detection of Ag⁺ in aqueous media

An organic/inorganic hybrid L@SBA-15 was constructed by the intermolecular hydrogen bond. XRD, TEM, FT-IR and TGA were used to characterize the grafting process. The results proved that L-Cl was successfully anchored into the channel of SBA-15 and that the primary ordered mesoporous structure of SBA-15 was well preserved. L@SBA-15 was utilized for Ag⁺determination in aqueous media. The correlative fluorescence signals are linearly proportional to log[Ag⁺] in the concentration region of 1 × 10⁻⁶ ∼ 4 × 10⁻⁵ mol/L, showing a low detection limit of 1.26 × 10⁻⁷ mol/L. A high sensitivity parameter of 0.97 was found. The competitive experiment confirmed that this sensor exhibited a high selectivity to Ag⁺. The high selectivity towards Ag⁺is mainly attributed to the spatial factor in the channel of SBA-15. The most attractive feature of this sensor is the excellent recovery, which indicates L@SBA-15 would be a promising candidate for practical application.