Department of Chemistry Jadavpur University, Kolkata 700 032, India.
Department of Biochemistry, University of Lausanne, Ch. des Boveresses 155, 1066 Epalinges, Switzerland.
J Mater Chem B. 2024 Sep 11;12(35):8791-8800. doi: 10.1039/d4tb01101e.
Here, we report the design and synthesis of a D⋯π⋯A-based fluorescent probe, ()-4-(4-(dibutylamine)-2-hydroxystyryl)-1-methylquinolin-1-ium (DHMQ), which is nonfluorescent in ∼100% PBS buffer medium due to a twisted intra molecular charge transfer (TICT) phenomenon and it becomes highly fluorescent (∼149 fold) in the presence of human serum albumin (HSA), owing to the restriction of its intramolecular free rotation inside the hydrophobic binding cavity of HSA. The site-selective fluorescence displacement assay and molecular docking studies clearly reveal that DHMQ selectively binds at subdomain IB of HSA. The 3/slope method was adopted to determine the limit of detection (LOD) value, which was as low as 2.39 nM in ∼100% PBS medium, indicating its high sensitivity towards HSA. The low dissociation constant value [ = (1.066 ± 0.017) μM] suggests a strong complexation between the DHMQ and HSA. Importantly, it has been demonstrated that DHMQ is capable of detecting HSA in real human serum and urine samples and was found to be suitable for live cell imaging of HSA.
在这里，我们报告了一种基于 D⋯π⋯A 的荧光探针（）-4-(4-(二丁基胺)-2-羟苯乙烯基)-1-甲基喹啉-1-鎓（DHMQ）的设计和合成，由于扭曲的分子内电荷转移（TICT）现象，它在约 100% PBS 缓冲介质中是非荧光的，而在存在人血清白蛋白（HSA）时，它变得高度荧光（约 149 倍），这是由于其在 HSA 的疏水结合腔内的分子内自由旋转受到限制。选择性荧光置换测定和分子对接研究清楚地表明，DHMQ 选择性地结合在 HSA 的亚域 IB 上。采用 3/slope 法测定检测限（LOD）值，在约 100% PBS 介质中的检测限值低至 2.39 nM，表明其对 HSA 具有高灵敏度。低解离常数值 [=（1.066±0.017）μM] 表明 DHMQ 与 HSA 之间存在强络合。重要的是，已经证明 DHMQ 能够在真实的人血清和尿液样本中检测 HSA，并且被发现适合于 HSA 的活细胞成像。
