A small molecular fluorescent sensor functionalized silica microsphere for detection and removal of mercury, cadmium, and lead ions in aqueous solutions

In this paper, we report a sensitive fluorescent sensor (FSCHP) for detection and removal of toxic metal ions (Cd2+, Hg2+ and Pb2+) in aqueous samples. FSCHP is a 2,2-dipicolylamine (DPA) modified naphthalimide fluorophore followed by immobilization to the surface of silica microsphere and support high affinity for Cd2+, Hg2+ and Pb2+. Metal adsorption by FSCHP was featured by an enhancement in its fluorescence intensity. The limit of detection of 36 nM for Cd2+, 48 nM for Hg2+, and 39 nM for Pb2+, was measured respectively. Moreover, FSCHP can also be used as adsorbent for the separation of toxic metal ions in the contaminated aqueous solution with high adsorptivity, and can be regenerated by acid treatment. The metal ion removal capacity of FSCHP was retained after five removal/regeneration cycles. (C) 2015 Elsevier B.V. All rights reserved.