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 Hg2+ in a heterogeneous system. The fluorescence enhancement of SBA-15-1 was attributed to the formation of a complex between SBA-15-1 and Hg2+ by a 1:1 complex ratio with the photo-induced electron transfer (PET) being forbidden. The sensor can be applied to the quantification of Hg2+ with a linear range covering from 1.0 x 10(-7) to 1.0 x 10(-5) M under the neutral condition. Most importantly, the fluorescence changes of the sensor are remarkably specific for Hg2+ in the presence of other metal ions. Moreover, the response of the sensor toward Hg2+ is fast and chemically reversible. In addition, the sensor has been used for the determination of Hg2+ in environmental samples with satisfactory results.