A Schiff base‐grafted nanoporous silica material as a reversible optical probe for Hg²⁺ ion in water

Abstract

A novel organic–inorganic silica‐based fluorescent probe was designed, synthesized and characterized by different techniques such as XRD, BET, TGA, and FT‐IR. The fluorescence properties of the probe were studied in the presence of a variety of metal‐ions in water. The results revealed that various metal‐ions negligibly vary the emission intensity of the probe except for Hg 2+ , which quenched the intensity dramatically. The selectivity of the probe toward Hg 2+ ion was further investigated in the presence of common competing metal‐ions and the results demonstrated the high selectivity of the probe toward Hg 2+ ion. The fluorescence emission of the probe was also studied as a function of the concentration of Hg 2+ ion. A nanomolar limit of detection was estimated for Hg 2+ , indicating a high sensitivity. Furthermore, the probe showed INHIBIT‐type logic behavior with Hg 2+ and H + as inputs. Also, the optimum pH range was studied in addition to reversibility and real world applicability of the probe.