Department of Physical Chemistry, College of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
Talanta. 2012 May 30;94:295-300. doi: 10.1016/j.talanta.2012.03.043. Epub 2012 Mar 29.
Rhodamine 6G (R6G) and 3-mercaptopropionic acid (MPA) capped-CdTe quantum dots (QDs) were conjugated by electrostatic interactions in aqueous solution. The R6G-QDs conjugate was utilized as a photoluminescence (PL) ratiometric sensor for the detection of glutathione (GSH). In this method, intentional introduction of GSH destroyed the conjugation of R6G and QDs, and induced regular PL change of R6G-QDs conjugates due to the competitive chelation between GSH and MPA ligand on the surface of QDs. The ratio of PL intensity of R6G (I(R6G)) to that of QDs (I(QDs)) in this conjugate was near linear toward the concentration of GSH in the range from 0.05 to 80 μM, and corresponding regression equation showed a good linear coefficient of 0.9954. The limit of detection of 15 nM in this proposed method was about 40-fold lower than that of other QDs-based PL sensors. Interferential experiments testified that R6G-QDs conjugates-based ratiometric PL sensor of GSH showed high selectivity over other related thiols and amino acids. Real sample assays further verified perfect analysis performance of the PL sensor of GSH. In comparison with conventional analytical techniques for the measurement of GSH, this ratiometric PL sensor was facile, economic, highly sensitive and selective.
罗丹明 6G（R6G）和巯基丙酸（MPA）修饰的碲化镉量子点（QDs）在水溶液中通过静电相互作用结合。R6G-QDs 缀合物被用作光致发光（PL）比率传感器，用于检测谷胱甘肽（GSH）。在该方法中，故意引入 GSH 破坏了 R6G 和 QDs 的结合，并由于 GSH 和 QDs 表面上的 MPA 配体之间的竞争螯合，导致 R6G-QDs 缀合物的 PL 发生规律变化。该缀合物中 R6G（I（R6G））的 PL 强度与 QDs（I（QDs））的 PL 强度之比与 GSH 的浓度在 0.05 至 80 μM 的范围内呈近线性关系，相应的回归方程显示出良好的线性系数为 0.9954。与其他基于 QDs 的 PL 传感器相比，该方法的检测限低至 15 nM，约低 40 倍。干扰实验证明，基于 R6G-QDs 缀合物的 GSH 比率 PL 传感器对其他相关巯基和氨基酸具有高选择性。实际样品分析进一步验证了 GSH 的 PL 传感器的完美分析性能。与用于测量 GSH 的常规分析技术相比，该比率 PL 传感器简便、经济、高度灵敏且选择性高。
