Experiment Center of Teaching & Learning, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Analyst. 2019 Jun 7;144(11):3676-3684. doi: 10.1039/c9an00280d. Epub 2019 May 14.
Biothiols, including cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and HS, play important roles in human physiological processes. However, it is a great difficulty to distinguish biothiols from each other because of their similar chemical properties. Based on Nile red, we have designed and synthesized a near-infrared fluorescent probe for discriminating Cys/Hcy from GSH/HS by a dual-channel detection method. Using an ether bond, near-infrared Nile red was attached to 7-nitrobenzofurazan to construct the probe. Due to the photo-induced electron transfer, the probe showed almost no fluorescence from the green to red emission band. But upon the addition of Cys (0-150 μM) or Hcy (0-200 μM), the probe exhibited a noteworthy fluorescence "turn-on" signal in two unique emission bands (Green and Red) with a fast response (within 30 min). In contrast, the probe displayed an increase in fluorescence only in the red channel when encountering GSH (0-70 μM) or HS (0-50 μM), and GSH/HS could be tested respectively by different response time. The limit of detection was calculated to be 0.09 μM (Cys), 0.30 μM (Hcy), 0.24 μM (GSH), and 0.04 μM (HS), respectively (based on S/N = 3). The desirable dual-channel detection could be achieved in serum samples and living cells. Moreover, the probe could be applied for bioimaging in mice, which indicated its potential application in the clinic.
生物硫醇，包括半胱氨酸（Cys）、同型半胱氨酸（Hcy）、谷胱甘肽（GSH）和 HS，在人体生理过程中发挥着重要作用。然而，由于它们具有相似的化学性质，因此很难将它们彼此区分开来。基于尼罗红，我们通过双通道检测方法设计并合成了一种用于区分 Cys/Hcy 与 GSH/HS 的近红外荧光探针。我们使用醚键将近红外尼罗红连接到 7-硝基苯并呋咱上，构建了该探针。由于光诱导电子转移，探针几乎没有从绿色到红色发射带的荧光。但是，当加入 Cys（0-150 μM）或 Hcy（0-200 μM）时，探针在两个独特的发射带（绿色和红色）中表现出显著的荧光“开启”信号，响应速度快（在 30 分钟内）。相比之下，当遇到 GSH（0-70 μM）或 HS（0-50 μM）时，探针仅在红色通道中显示荧光增加，并且可以通过不同的响应时间分别测试 GSH/HS。检测限分别计算为 0.09 μM（Cys）、0.30 μM（Hcy）、0.24 μM（GSH）和 0.04 μM（HS）（基于 S/N = 3）。该探针在血清样品和活细胞中可以实现理想的双通道检测。此外，该探针可用于小鼠的生物成像，表明其在临床上具有潜在的应用。
