Department of Chemistry , Indian Institute of Technology Guwahati 781039 , India.
Anal Chem. 2018 Jun 19;90(12):7561-7568. doi: 10.1021/acs.analchem.8b01181. Epub 2018 Jun 5.
Two cyanine-based fluorescent probes, ( E)-2-(4-(diethylamino)-2-hydroxystyryl)-3-ethyl-1,1-dimethyl-1 H-benzo[ e]indol-3-ium iodide (L) and ( E)-3-ethyl-1,1-dimethyl-2-(4-nitrostyryl)-1 H-benzo[ e]indol-3-ium iodide (L), have been designed and synthesized. Of these two probes, the twisted-intramolecular-charge-transfer (TICT)-based probe, L, can preferentially self-assemble to form nanoaggregates. L displayed a selective turn-on fluorescence response toward human and bovine serum albumin (HSA and BSA) in ∼100% aqueous PBS medium, which is noticeable with the naked eye, whereas L failed to sense these albumin proteins. The selective turn-on fluorescence response of L toward HSA and BSA can be attributed to the selective binding of probe L with HSA and BSA without its interfering with known drug-binding sites. The specific binding of L with HSA led to the disassembly of the self-assembled nanoaggregates of L, which was corroborated by dynamic-light-scattering (DLS) and transmission-electron-microscopy (TEM) analysis. Probe L has a limit of detection as low as ∼6.5 nM. The sensing aptitude of probe L to detect HSA in body fluid and an artificial-urine sample has been demonstrated.
两种基于菁染料的荧光探针，（E）-2-（4-（二乙氨基）-2-羟基苯乙烯基）-3-乙基-1,1-二甲基-1H-苯并[e]吲哚-3-碘化物（L）和（E）-3-乙基-1,1-二甲基-2-（4-硝基苯乙烯基）-1H-苯并[e]吲哚-3-碘化物（L），已被设计和合成。在这两种探针中，基于扭曲分子内电荷转移（TICT）的探针 L 可以优先自组装形成纳米聚集体。在约 100%水相 PBS 介质中，L 对人血清白蛋白（HSA）和牛血清白蛋白（BSA）表现出选择性的开启荧光响应，肉眼可见，而 L 未能检测到这些白蛋白蛋白。L 对 HSA 和 BSA 的选择性开启荧光响应归因于探针 L 与 HSA 和 BSA 的选择性结合，而不会干扰已知的药物结合位点。L 与 HSA 的特异性结合导致 L 的自组装纳米聚集体的解组装，这一点得到了动态光散射（DLS）和透射电子显微镜（TEM）分析的证实。探针 L 的检测限低至约 6.5 nM。探针 L 对体液和人工尿液样本中 HSA 的检测能力已得到证明。
