Colorimetric Assay for Determination of Lead (II) Based on Its Incorporation into Gold Nanoparticles during Their Synthesis

Sensors

Nan Ding²  Qian Cao²  Hong Zhao²  Yimin Yang²  Lixi Zeng²  Yujian He²  Kaixiang Xiang¹ 

[1] Huaihua Medical College, Hunan, 418000, China; E-Mail:;College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, 19A YuQuan Road, Beijing 100049, China; E-Mails:

关键词: visual detection;    lead ions;    gold nanoparticles;    gallic acid;   

DOI  :  10.3390/s101211144

来源: mdpi

【 摘 要 】

In this report, we present a new method for visual detection of Pb²⁺. Gold nanoparticles (Au-NPs) were synthesized in one step at room temperature, using gallic acid (GA) as reducer and stabilizer. Pb²⁺ is added during the gold nanoparticle formation. Analysis of Pb²⁺ is conducted by a dual strategy, namely, colorimetry and spectrometry. During Au-NPs synthesis, addition of Pb²⁺ would lead to formation of Pb-GA complex, which can induce the aggregation of newly-formed small unstable gold nanoclusters. Consequently, colorimetric detection of trace Pb²⁺ can be realized. As the Pb²⁺ concentration increases, the color turns from red-wine to purple, and finally blue. This method offers a sensitive linear correlation between the shift of the absorption band (Δλ) and logarithm of Pb²⁺ concentration ranging from 5.0 × 10⁻⁸ to 1.0 × 10⁻⁶ M with a linear fit coefficient of 0.998, and a high selectivity for Pb²⁺ detection with a low detection limit down to 2.5 × 10⁻⁸ M.

【 授权许可】

CC BY   
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