Detection and removal of Hg2+ based on mesoporous silica material functionalized by naphthalimide in aqueous solution

An inorganic-organic silica material (SBA-15-1), prepared by immobilization of the naphthalimide derivative within the channels of the mesoporous silica material SBA-15, is characterized by several spectroscopic methods. SBA-15-1 can be used as a chemical sensor for detecting and removing Hg(2+) in a heterogeneous system. The fluorescence enhancement of SBA-15-1 was attributed to the formation of a complex between SBA-15-1 and Hg(2+) by a 1:1 complex ratio with the photo-induced electron transfer (PET) being forbidden. The sensor can be applied to the quantification of Hg(2+) with a linear range covering from 1.0 × 10(-7) to 1.0 × 10(-5) M under the neutral condition. Most importantly, the fluorescence changes of the sensor are remarkably specific for Hg(2+) in the presence of other metal ions. Moreover, the response of the sensor toward Hg(2+) is fast and chemically reversible. In addition, the sensor has been used for the determination of Hg(2+) in environmental samples with satisfactory results.