Facile and highly selective sensing of hypochlorous acid in aqueous solution and living cells by using as-prepared WSe2 quantum dots

Yang, Haimei; Zhao, Qianghong; Wang, Xian; Wu, Yu; Su, Yu-Chen; Wei, Weili

doi:10.1016/j.snb.2021.129782

Cited by 10 publications

(1 citation statement)

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“…Despite these experimental results showing enhanced PL properties in the TMDs-QDs with a size comparable to the exciton Bohr radius, it is still vague whether quantum confinement is a dominant mechanism in TMDs-QDs with a size larger than the exciton Bohr radius and with an edge structure sensitively varied by pH change and/or functional groups. It was reported that MoSe 2 -QDs and MoS 2 -QDs have a pH-dependent PL [ 12 , 25 ], but the pH-independent PL property of WSe 2 -QDs was also demonstrated [ 26 ]. These contrasting results are controversial and have not been explained yet.…”

Section: Introductionmentioning

confidence: 99%

Competitive Effects of Oxidation and Quantum Confinement on Modulation of the Photophysical Properties of Metallic-Phase Tungsten Dichalcogenide Quantum Dots

et al. 2023

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Metallic-phase transition metal dichalcogenide quantum dots (TMDs-mQDs) have been reported in recent years. However, a dominant mechanism for modulating their intrinsic exciton behaviors has not been determined yet as their size is close to the Bohr radius. Herein, we demonstrate that the oxidation effect prevails over quantum confinement on metallic-phase tungsten dichalcogenide QDs (WX2-mQDs; X = S, Se) when the QD size becomes larger than the exciton Bohr radius. WX2-mQDs with a diameter of ~12 nm show an obvious change in their photophysical properties when the pH of the solution changes from 2 to 11 compared to changing the size from ~3 nm. Meanwhile, we found that quantum confinement is the dominant function for the optical spectroscopic results in the WX2-mQDs with a size of ~3 nm. This is because the oxidation of the larger WX2-mQDs induces sub-energy states, thus enabling excitons to migrate into the lower defect energy states, whereas in WX2-mQDs with a size comparable to the exciton Bohr radius, protonation enhances the quantum confinement.

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Section: Introductionmentioning

confidence: 99%