Shandong Institute for Food and Drug Control, Jinan 250101, China.
Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 210009, China.
Talanta. 2018 Sep 1;187:295-301. doi: 10.1016/j.talanta.2018.05.046. Epub 2018 May 12.
As a widely used reducing agent, 1, 4-dithiothreitol (DTT) plays important roles in the fields of biology, biochemistry, and biomedicine. The development of facile and fast methods for DTT detection is urgent and necessary. In this article, we rationally constructed a novel two-photon fluorescent probe 6-(methylsulfinyl)-2-phenyl-1H-benzo[de]isoquinoline-1,3(2 H)-dione (NC-DTT) for detecting DTT, which employed the 1,8-naphthalimide and sulfoxide as the fluorophore and receptor unit respectively. The sulfoxide group in probe NC-DTT can be reduced by DTT to compound 6-(methylthio)-2-phenyl-1H-benzo[de]isoquinoline-1,3(2 H)-dione (NC), which could emit strong fluorescence with large Stokes shift presumably due to the enhanced intramolecular charge transfer (ICT). This probe responded to DTT quickly (within 1000 s) and showed satisfactory selectivity. A good linearity between fluorescence intensity and the concentration of DTT in the range of 0 - 700 μM was observed, and the detection limit towards DTT was 1.4 × 10 M. Furthermore, the probe was successfully employed in one- and two-photon imaging of DTT in HepG2 cells with low cytotoxicity.
作为一种广泛使用的还原剂，1,4-二硫苏糖醇（DTT）在生物学、生物化学和生物医学领域发挥着重要作用。开发简便、快速的 DTT 检测方法是紧迫和必要的。在本文中，我们合理构建了一种新型的用于检测 DTT 的双光子荧光探针 6-（甲亚磺酰基）-2-苯基-1H-苯并[de]异喹啉-1,3(2H)-二酮（NC-DTT），它分别采用了萘酰亚胺和亚砜作为荧光团和受体单元。探针 NC-DTT 中的亚砜基团可被 DTT 还原为化合物 6-（甲硫基）-2-苯基-1H-苯并[de]异喹啉-1,3(2H)-二酮（NC），这可能由于增强了分子内电荷转移（ICT）而导致强荧光和大斯托克斯位移。该探针对 DTT 响应迅速（在 1000s 内），且具有良好的选择性。在 0-700μM 范围内，荧光强度与 DTT 浓度之间呈现出良好的线性关系，对 DTT 的检测限为 1.4×10 M。此外，该探针还成功地用于 HepG2 细胞中 DTT 的单光子和双光子成像，且具有低细胞毒性。
