Surfactant stabilized AgNPs as a colorimetric probe for simple and selective detection of hypochlorite anion (ClO-) in aqueous solution: Environmental sample analysis

Herein, the development of a colorimetric probe for selective detection of hypochlorite ion (ClO-) using cetylpyridinium bromide (CPB) capped silver nanoparticles (CPB-AgNPs) in aqueous solution is reported. The absorbance of the CPB-AgNPs was significantly decreased in presence of ClO- resulting in the color change from yellowish brown to colorless due to inducing aggregation of CPB-AgNPs with CIO-. The interaction between ClO- and CPB-AgNPs is studied by some analytical techniques such as UV-vis absorption spectroscopy, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and zeta potential measurements. Under the optimum condition, the calibration plot of (A(0)-A) against concentration of ClO- was linear in the range of 0.5-4.5 mu g mL(-1) with a correlation coefficient of 0.9927. The concentration of ClO- is quantitatively determined from an UV-vis spectrophotometer with a Limit of Detection (LOD) is 0.45 mu g mL(-1). This method shows excellent selectivity towards ClO- checked over other interfering anions. The accuracy and reliability of the methods were further ascertained for the detection of ClO- from environmental samples via standard-addition method, with percentage recoveries in the range of 98.80-102.94%. The plausible reason for color change is also discussed. The proposed method is simple, rapid, specific and highly selective with good precision. (C) 2015 Elsevier B.V. All rights reserved.