Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, Shandong Key Laboratory of Biochemical Analysis, Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
An Chem-Tech Co., Ltd, Guangzhou, 510665, People's Republic of China.
Mikrochim Acta. 2018 Oct 1;185(10):485. doi: 10.1007/s00604-018-3024-y.
Near infrared (NIR) emitting semiconductor quantum dots can be excellent fluorescent nanoprobes, but the poor biodegradability and potential toxicity limits their application. The authors describe a fluorescent system composed of graphene quantum dots (GQDs) as NIR emitters, and novel MnO nanoflowers as the fluorescence quenchers. The system is shown to be an activatable and biodegradable fluorescent nanoprobe for the "turn-on" detection of intracellular glutathione (GSH). The MnO-GQDs nanoprobe is obtained by adsorbing GQDs onto the surface of MnO nanoflowers through electrostatic interaction. This results in the quenching of the NIR fluorescence of the GQDs. In the presence of GSH, the MnO-GQDs nanoprobe is degraded and releases Mn and free GQDs, respectively. This gives rise to increased fluorescence. The nanoprobe displays high sensitivity to GSH and with a 2.8 μM detection limit. It integrates the advantages of NIR fluorescence and biodegradability, selectivity, biocompatibility and membrane permeability. All this makes it a promising fluorescent nanoprobe for GSH and for cellular imaging of GSH as shown here for the case of MCF-7 cancer cells. Graphical abstract A biodegradable NIR fluorescence nanoprobe (MnO-GQDs) for the "turn-on" detection of GSH in living cell was established, with the NIR GQD as the fluorescence reporter and the MnO nanoflower as the fluorescence quencher.
近红外（NIR）发射半导体量子点可以作为极好的荧光纳米探针，但较差的生物降解性和潜在毒性限制了它们的应用。作者描述了一种由石墨烯量子点（GQDs）作为 NIR 发射器和新型 MnO 纳米花作为荧光猝灭剂组成的荧光体系。该体系被证明是一种可激活和可生物降解的荧光纳米探针，可用于细胞内谷胱甘肽（GSH）的“开启”检测。MnO-GQDs 纳米探针是通过静电相互作用将 GQDs 吸附到 MnO 纳米花表面上而获得的。这导致 GQDs 的 NIR 荧光猝灭。在 GSH 的存在下，MnO-GQDs 纳米探针被降解并分别释放 Mn 和游离的 GQDs，从而导致荧光增强。该纳米探针对 GSH 具有高灵敏度，检测限为 2.8 μM。它集成了近红外荧光和生物降解性、选择性、生物相容性和膜通透性的优点。所有这些使其成为一种很有前途的荧光探针，可用于检测 GSH 并对 GSH 进行细胞成像，如 MCF-7 癌细胞的情况所示。
