Design and evaluation of optical mesocaptor for the detection/recovery of Au(III) from an urban mine

Natural resources, especially precious metal ions such as gold, are depleting because of their continuous use, which increases the importance of their recovery/recycling processes. The gold recovery system that we offer is cutting edge and unlike any other technique. Our strategy offers an effective, naked-eye detection/recovery of gold ions from simulated and real urban mine aquatic samples using mesocaptor monoliths with unique features. It can be done quickly, easily, and without the presence of dangerous or irritating fumes. The optical mesocaptor was fabricated by the immobilization of a 6-hydroxy-5-(4-sulfonatophenylazo)-2-naphthalene-sulfonic acid disodium salt probe into large, open, cage-pored, three-dimensional cubic mesostructures with micrometer-sized monolith particles. This simple strategy can satisfy analytical needs. It is characterized by simplicity in fabrication design, loading capacity, selectivity, and sensitivity, with a fast response time in the detection/recovery of ultra-trace concentrations of Au(III) ions without pre-concentration. The adsorbed Au(III) was eluted/extracted with stripping agents, and the mesocaptor was simultaneously regenerated for the subsequent recovery process. Based on our results, this new class of optical mesocaptor exhibits a long-term stability of recognition and signaling functionalities of Au(III) ions. It generally provides extraordinary sensitivity, selectivity, reusability, and fast kinetic detection and quantification of Au(III) ions in aquatic samples. (C) 2014 Elsevier B.V. All rights reserved.