Masking agent-controlled discriminative Hg2+ and Cu2+ sensing by quinonediimine dye formation of aniline-functionalized silica nanoparticles

Abstract

A novel masking agent-controlled discriminative Hg2+- and Cu2+-selective reaction-based sensing system was investigated. Signaling was carried out by the metal-assisted oxidative coupling of aniline-functionalized silica nanoparticles with 3-methyl-2-benzothiazolinone hydrazone (MBTH) to yield a highly colored quinonediimine dye. The sensing system revealed prominent colorimetric signaling behavior towards Hg2+ and Cu2+ ions. Especially, discriminative signaling for cross-interfering Hg2+ and Cu2+ in the presence of their counterpart metal ions was accomplished using citrate and iodide, respectively, as corresponding masking agents. In addition, practical application to the determination of Hg2+ and Cu2+ in simulated semiconductor wastewater was achieved using a readily available office scanner as data capturing device, which is convenient for field application. (C) 2017 Elsevier B.V. All rights reserved.