Tunable single and double emission semiconductor nanocrystal quantum dots: a multianalyte sensor
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Updated: Feb 12, 2026

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Ratneshwar Kumar Ratnesh1, Mohan Singh Mehata1
1Laser-Spectroscopy Laboratory, Department of Applied Physics, Delhi Technological University, Bawana Road, Delhi-110042, India.
Abstract:
We have prepared stable colloidal CdTe and CdTe/ZnS core-shell quantum dots (QDs) using hot injection chemical route. The developed CdTe QDs emit tunable single and dual photoluminescence (PL) bands, originating from the direct band edge and the surface state of QDs, as evident by the steady-state and time-resolved spectroscopy. The developed CdTe and CdTe/ZnS QDs act as optical sensors for the detection of metal ions (e.g., Fe2+ and Pb2+) in the feed water. The PL quenching in the presence of analytes has been examined by both the steady-state and time-resolved PL spectroscopy. The linear Stern-Volmer (S-V) plots obtained for PL intensity and lifetime as a function of metal ion concentration demonstrates the diffusion-mediated collisional quenching as a dominant mechanism together with the possibility of fluorescence resonance energy transfer. Thus, the prepared core and core-shell QDs which cover a broad spectral range of white light with high quantum yield (QY) are highly sensitive to the detection of metal ions in feed water and are also important for biological applications (Ratnesh and Mehata 2017 Spectrochim. Acta A: Mol. Biomol. Spectro. 179 201-10).
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