Highly Selective and Sensitive Colorimetric Determination of Cr3 + Ion by 4-Amino-5-Methyl-4H-1,2,4-Triazole-3-Thiol Functionalized Au Nanoparticles Publisher Pubmed



Shahrivari S¹ ; Faridbod F¹ ; Ganjali MR^{1, 2}
Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy Published:2018

Abstract

In this work, a rapid, selective naked eyes colorimetric chemical probe for the detection of Cr3 + was developed based on functionalization of gold nanoparticles. For this purpose, surface of Au NPs was functionalized using 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol (AMTT). Through colorimetric studies, it was found that in the presence of Cr3 + ions, AMTT-Au NPs instantly aggregated and resulted in a color change of the solution from red to blue. The color change of AMTT-Au NPs due to the aggregation induced by Cr3 + can be seen with even naked eyes and also by UV–Vis spectroscopy with a detection limit of 1.8 μM and 0.1 μM, respectively. AMTT-Au NPs showed excellent selectivity toward Cr3 + compared to other cations tested, including K+, Na+, Cs+, Fe3 +, Ni2 +, Cu2 +, Co2 +, Zn2 +, Ba2 +, Ca2 +, Mg2 +, Cd2 +, Pb2 +, Hg2 + ions and especially all trivalent lanthanide ions. The absorbance ratio (A650/A525) was linear toward Cr3 + concentrations in the range of 0.6–6.1 μM (R2 = 0.996). The best response was achieved over a pH range of 3–5. Furthermore, the proposed colorimetric method based on AMTT-Au NPs was successfully used for Cr3 + ion detection in plasma sample and some water samples. © 2017 Elsevier B.V.