Dual-mode fluorescence and colorimetric sensing of sulfide anion in natural water based on near-infrared Ag2S quantum dots and MnO2 nanosheets complex

Xiufeng Wang; Yao Jin; Wenhui Ai; Siqi Wang; Zhiqing Zhang; Ting Zhou; Fang Wang; Guodong Zhang

doi:10.1016/j.saa.2023.123626

Dual-mode fluorescence and colorimetric sensing of sulfide anion in natural water based on near-infrared Ag₂S quantum dots and MnO₂ nanosheets complex

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Feb 15:307:123626. doi: 10.1016/j.saa.2023.123626. Epub 2023 Nov 7.

Authors

Xiufeng Wang¹, Yao Jin², Wenhui Ai², Siqi Wang², Zhiqing Zhang³, Ting Zhou², Fang Wang², Guodong Zhang²

Affiliations

¹ Department of Chemistry, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China. Electronic address: xfwang@upc.edu.cn.
² Department of Chemistry, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China.
³ Department of Chemistry, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China. Electronic address: zhangzq@upc.edu.cn.

PMID: 37952425
DOI: 10.1016/j.saa.2023.123626

Abstract

Near infrared (NIR) emission Ag₂S quantum dots (QDs) are of great value for biochemical sensing with strong anti-interference and low toxicity. Herein, NIR fluorescence Ag₂S QDs were synthesized successfully. Combined with the excellent oxidase-like characteristics of manganese dioxide (MnO₂) nanosheets, a fluorescence and colorimetric dual-mode sensor for sulfide anion was developed. MnO₂ nanosheets could effectively catalyze the oxidation of TMB to produce blue TMB oxide (ox TMB), at the same time, the fluorescence of Ag₂S QDs could be effectively quenched by fluorescence internal filtration effect (IFE) and dynamic quenching effect. The enzyme-like activity was weakened and the NIR fluorescence of Ag₂S QDs was restored when sulfide anion (S^2-) was added, due to the reduction of MnO₂ to Mn²⁺.The linear ranges for fluorescence and colorimetric analysis of S^2- were 2-250 μM and 0.3-50 μM, with detection limits of 0.6 and 0.215 μM, correspondingly. The dual-mode sensor had a wider detection range, higher sensitivity and shorter reaction time, which could be used for highly selective detection of S^2- in different concentration ranges. In addition, it had been successfully applied to the determination of sulfide in water samples with satisfactory accuracy and sensitivity.

Keywords: Ag(2)S quantum dots; Dual-mode sensor; MnO(2) nanosheets; Near-infrared fluorescence; Sulfide anion.