Copper ion detection with improved sensitivity through catalytic quenching of gold nanocluster fluorescence

Publication date: 1 September 2018
Source:Talanta, Volume 187
Author(s): Minchuan Luo, Junwei Di, Liang Li, Yifeng Tu, Jilin Yan
In this report, a sensitive fluorescence detection of copper (Ⅱ) ion was developed. Although itself only a weak quencher toward gold nanocluster fluorescence, this ion functioned as a catalyst that accelerated the oxidation of iodide into iodine by a strong oxidant. The so-produced iodine quenched the nanocluster fluorescence through an efficient etching reaction, which rendered a much improved sensitivity for copper detection. Under the optimal conditions, the extent of quenching was found linear to the amount of copper in the range of 0.8–80 nM, and this strategy was capable of detecting copper ion as low as 0.33 nM. The method was selective and was successfully applied for related measurement in practical samples.

Graphical abstract

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