Yu Changmin, Wu Yinglong, Zeng Fang, Wu Shuizhu
College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China.
J Mater Chem B. 2013 Sep 7;1(33):4152-4159. doi: 10.1039/c3tb20686f. Epub 2013 Jul 9.
As an endogenously generated signal-inducing agent in the immune, cardiovascular and nervous systems, nitric oxide (NO) is involved in various biological processes and a large number of pathologies. Hence, sensitive and reliable detection of NO in biological samples and inside living cells has been of great interest. Herein, we reported a carbon-dot-based fluorescent ratiometric nanosensor for NO detection in water and imaging in living cells. Ratiometric sensing is realized through the fluorescence resonance energy transfer (FRET) process, and the carbon dots (CDs) serve as both the energy donor and the anchoring site for the NO probe moiety, which turns into the energy acceptor in the presence of NO. This nanosensor is highly selective for NO, and is operable in totally aqueous media with a very low detection limit of 3 nM. Due to the biocompatible nature and small size of the carbon dots, the nanosensor exhibits very low cytotoxicity and can easily permeate through the cell membrane. The nanosensor is capable of tracking the exogenous NO levels in several cell lines such as Hela, L929 and Raw 264.7 cells, and it can be also used to visualize the endogenously produced NO in the Raw 264.7 macrophage cell line.
作为免疫、心血管和神经系统中内源性产生的信号诱导剂，一氧化氮（NO）参与各种生物过程和大量病理过程。因此，对生物样品和活细胞内的NO进行灵敏可靠的检测一直备受关注。在此，我们报道了一种基于碳点的荧光比率纳米传感器，用于水中NO的检测和活细胞成像。比率传感通过荧光共振能量转移（FRET）过程实现，碳点（CDs）既作为能量供体，又作为NO探针部分的锚定位点，在NO存在时，NO探针部分转变为能量受体。这种纳米传感器对NO具有高度选择性，可在完全水性介质中操作，检测限低至3 nM。由于碳点具有生物相容性和小尺寸，该纳米传感器表现出非常低的细胞毒性，并且可以很容易地穿透细胞膜。该纳米传感器能够跟踪多种细胞系（如Hela、L929和Raw 264.7细胞）中的外源性NO水平，还可用于可视化Raw 264.7巨噬细胞系中内源性产生的NO。
