Abstract
Most of the reports suggest that liquid exfoliated WS2-QDs are unstable; therefore the need of present day is to develop a novel synthesis route for producing long-term stable WS2-QDs. Herein, we report a bottom-up single-step hydrothermal growth of in situ functionalized blue fluorescent WS2-QDs with stable fluorescence in aqueous media without subsequent treatments. Presence of various functional groups over the surface of f-WS2-QDs provides high solubility and stability to f-WS2-QDs in aqueous media preserving its fluorescence. Further, photoluminescence property of f-WS2-QDs has been employed to devise an optical sensor with a high sensitivity (KD ∼104 M-1) and selectivity for ferric (Fe3+) ions. Under the optimal condition, response of the sensor is found to be linear in the range of 0-55 μM with a limit of detection (LOD) of 1.32 μM, which is within the maximum permissible level of Fe3+ (∼5.4 μM) in human drinking water by the USEPA. Further, we have also carried out a detailed evaluation on fluorescence quenching kinetics of f-WS2-QDs. Nonlinear behavior of S-V plot and TRPL measurements suggest that quenching is a mixed phenomenon of dynamic as well as static processes.
Original language | English |
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Pages (from-to) | 566-576 |
Number of pages | 11 |
Journal | ACS Applied Nano Materials |
Volume | 2 |
Issue number | 1 |
DOIs | |
State | Published - 25 Jan 2019 |
Keywords
- TRPL
- WS
- fluorescence quenching
- hydrothermal synthesis
- quantum dots
- quantum yield
ASJC Scopus subject areas
- General Materials Science