A green, rapid and effcient dual-sensors for highly selective and sensitive detection of cation (Hg2+) and anion (S2-) ions based on cms/agnps composites

Abstract

Detection of mercury (Hg2+) and sulfide (S2-), universal and well-known toxic ions, is cruciai in monitoring several diseases. How to design and fabricate the high-performance sensor for simultaneously and accurately detecting the Hg2+ and S2- is criticai. Herein, we proposed a novel and convenient strategy for optical detection of Hg2+ and S2- by employing a carboxymethyl cellulose sodium/silver nanoparticle (CMS/AgNPs) colloidal solution, in which AgNPs were used as monitor for Hg2+ and S2-, and the CMS was utilized as both the stabilizer and the hydropliilic substrate for AgNPs. Well-identifiable peaks for Hg2+ and S2- were obtained in water based on UV-VIS absorption spectra, the absorbance intensity and/or position of nano-silver vary with the addition of Hg2++ cation and S2- anion, accompanying with color change. Impressively, the optimal AgNPs anchored CMS exhibited a high sensitivity and selectivity toward Hg2+ and S2-, the change in absorbance was linear with the concentration of Hg2+ (0-50 μM) and S2- (15-70 μM), and the lowest limits of detection (LOD) were 1.8 x 10-8 M and 2.4 x 10-7 M, respectively More importantly, owing to the superior properties in testing Hg2+ and S2-, the fabricated sensor was successfully applied for detection of target ions in lake and tap water samples. Ali these good results implied that the designed strategy and as-designed samples is promising in detecting cation (Hg2+) and anion (S2-) ions and open up new opportunities for selecting other kinds of ions.