Laser-Spectroscopy Laboratory, Department of Applied Physics, Delhi Technological University, Bawana Road, Delhi-110042, India.
Methods Appl Fluoresc. 2018 Apr 25;6(3):035006. doi: 10.1088/2050-6120/aaba8a.
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., Fe and Pb) 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).
我们使用热注射化学法制备了稳定的胶体 CdTe 和 CdTe/ZnS 核壳量子点（QDs）。所开发的 CdTe QD 发射可调谐的单和双光致发光（PL）带，源自 QD 的直接带边和表面态，这可以通过稳态和时间分辨光谱得到证明。所开发的 CdTe 和 CdTe/ZnS QD 可用作光学传感器，用于检测给水中的金属离子（例如 Fe 和 Pb）。通过稳态和时间分辨 PL 光谱研究了存在分析物时的 PL 猝灭。PL 强度和寿命与金属离子浓度的线性 Stern-Volmer（S-V）图表明，扩散介导的碰撞猝灭是主要机制，同时还存在荧光共振能量转移的可能性。因此，所制备的核和核壳 QD 具有高量子产率（QY），覆盖了宽范围的白光光谱，对给水中金属离子的检测非常敏感，同时也对生物应用很重要（Ratnesh 和 Mehata 2017 Spectrochim. Acta A: Mol. Biomol. Spectro. 179 201-10）。
