Smartphone-assisted fluorometric detection of heavy metals using gold nanoclusters with sequential addition of carbon dots
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Issued Date
2025-12-01
Resource Type
ISSN
0026265X
Scopus ID
2-s2.0-105019709398
Journal Title
Microchemical Journal
Volume
219
Rights Holder(s)
SCOPUS
Bibliographic Citation
Microchemical Journal Vol.219 (2025)
Suggested Citation
Permpool I., Maknun L., Watthanaphanit A., Sumranjit J., Siripinyanond A. Smartphone-assisted fluorometric detection of heavy metals using gold nanoclusters with sequential addition of carbon dots. Microchemical Journal Vol.219 (2025). doi:10.1016/j.microc.2025.115928 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/112868
Title
Smartphone-assisted fluorometric detection of heavy metals using gold nanoclusters with sequential addition of carbon dots
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Abstract
A smartphone-assisted fluorometric method was developed for the detection of lead (Pb<sup>2+</sup>), mercury (Hg<sup>2+</sup>), and copper (Cu<sup>2+</sup>) using gold nanoclusters (AuNCs) as fluorescent probes. The detection mechanism is based on fluorescence enhancement by Pb<sup>2+</sup> and quenching by Hg<sup>2+</sup> and Cu<sup>2+</sup>. To enhance detection sensitivity and visual contrast, carbon dots (CDs) were added into the reaction mixture through serial addition at AuNCs/CDs ratio of 1:0.02 and 1:0.05. A key novelty of this work is the integration of tunable AuNCs/CDs ratios with smartphone-based RGB analysis, enabling semi-quantitative detection without the need for advanced instrumentation. RGB values extracted using smartphone application facilitated both quantitative and qualitative analysis of heavy metal ions. The method demonstrated selectivity for Pb<sup>2+</sup>, Hg<sup>2+</sup>, and Cu<sup>2+</sup> with limits of detection (LOD) of 220 μg·L<sup>−1</sup>, 100 μg·L<sup>−1</sup>, and 390 μg·L<sup>−1</sup>, respectively. In addition, flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (FlFFF-ICP-MS) revealed AuNC aggregation in response to increasing Pb<sup>2+</sup> concentrations. The AuNCs/CDs probe provide the high %recovery with relative standard deviations (RSDs) below 10 %, indicating good precision and effective detection of Hg<sup>2+</sup> and Pb<sup>2+</sup> for water samples. This proposed method offers a simple, low-cost, and portable approach for detecting heavy metals in water samples.