College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou Key Laboratory of Functional Nanomaterial and Medical Theranostic, Zhengzhou University, Zhengzhou 450001, China.
Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan & Education Ministry of P.R. China, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Feb 15;267(Pt 2):120492. doi: 10.1016/j.saa.2021.120492. Epub 2021 Oct 11.
In this work, cysteamine (CA) stabilized CdTe quantum dots (QDs) (CA-CdTe QDs) and sodium citrate stabilized gold nanoparticles (AuNPs) were prepared. Because of the strong electrostatic interaction and spectral overlap of emission spectrum of CA-CdTe QDs and absorption spectrum of AuNPs, a highly effective fluorescence resonance energy transfer (FRET) system was formed and the fluorescence of CA-CdTe QDs was strongly quenched. The synthesized CA-CdTe and AuNPs were self-assembled to large clusters due to the electrostatic attraction and the fluorescence of CA-CdTe was sharply quenched as a result of FRET. Under the optimum pH of 5.5, the positive GSH could assemble with negative AuNPs through electrostatic interaction and destroy the FRET system of CA-CdTe and AuNPs, due to the red shift of absorption wavelength of AuNPs caused by aggregation. The fluorescence of CA-CdTe recovered, and the recovered fluorescence efficiency shows a linear function against the GSH concentrations from 6.7 nM to 0.40 μM, with a detecting limit of 3.3 nM. The quenched emission of CA-CdTe could be recovered attributed to the aggregation of AuNPs by GSH. Under optimal conditions, the sensing system was successfully applied in the detection of GSH in real human blood plasma samples with a recovery of 99.5-102.3%, showing a promising future for the highly sensitive and selective GSH detection in the human blood plasma samples.
在这项工作中，制备了半胱胺（CA）稳定的碲化镉量子点（CA-CdTe QDs）和柠檬酸钠稳定的金纳米粒子（AuNPs）。由于 CA-CdTe QDs 的发射光谱与 AuNPs 的吸收光谱之间存在强烈的静电相互作用和光谱重叠，因此形成了一个高效的荧光共振能量转移（FRET）系统，从而强烈猝灭了 CA-CdTe QDs 的荧光。由于静电吸引，合成的 CA-CdTe 和 AuNPs 自组装成大的聚集体，结果是由于 FRET，CA-CdTe 的荧光被急剧猝灭。在最佳 pH 值为 5.5 时，带正电荷的 GSH 可以通过静电相互作用与带负电荷的 AuNPs 组装，并由于 AuNPs 的聚集导致吸收波长红移，破坏 CA-CdTe 和 AuNPs 的 FRET 系统。CA-CdTe 的荧光恢复，恢复的荧光效率与 GSH 浓度从 6.7 nM 到 0.40 μM 呈线性关系，检测限为 3.3 nM。由于 GSH 引起的 AuNPs 聚集，猝灭的 CA-CdTe 发射可以被恢复。在最佳条件下，该传感系统成功应用于实际人血浆样品中 GSH 的检测，回收率为 99.5-102.3%，为在人血浆样品中进行高灵敏度和选择性 GSH 检测展示了广阔的前景。
