Herein, we develop a rapid, sensitive and selective approach for
the colorimetric detection of DA using AuNPs, with theoretical simplicity
and low technical demands. In alkaline solution, DA capps and
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Talanta
http://dx.doi.org/10.1016/j.talanta.2015.02.038
0039-9140/Crown Copyright & 2015 Published by Elsevier B.V. All rights reserved.
n Corresponding author.
E-mail address: ymleng@nynu.edu.cn (Y. Leng).
Talanta 139 (2015) 89–95
aggregates AuNPs (DA-AuNPs) due to the covalent and noncovalent
interactions between DA and AuNPs [43,44]. The DA-AuNPs are
modified by the hydrolysate of thioglycolic acid (TGA2) through Au–
S bonds [30,34]. Due to the strong hydrogen-bonds (NH⋯OC and
OH⋯OC) formed between TGA2 and DA, the AuNPs are further
aggregated [45,46]. With the increase of DA concentrations, the color
of AuNPs gradually changes from an initial red to purple, then gray
and finally yellow