School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
Talanta. 2017 May 15;167:253-259. doi: 10.1016/j.talanta.2017.02.027. Epub 2017 Feb 13.
In this work, we report a novel use of the distinctive metal-to-ligand charge-transfer (MLCT) absorption properties of the chromogenic Fe(BPDS) (BPDS=bathophenanthroline disulfonic acid) reporter for the visual detection of β-galactosidase (β-Gal) activity and sandwich immunoassay. The enzymatic hydrolysis of the substrate p-aminophenyl-β-D-galactopyranoside can switch on the reduction of Fe to Fe and the subsequent complexation of Fe with the BPDS ligand to generate the Fe(BPDS) reporter, leading to the appearance of the intense MLCT absorption band at 535nm and the colorless-to-red color change of the solution. Simply through a single step, the activity of β-Gal can be sensitively and selectively detected within the dynamic range of 0-220mUmL, with a limit of detection (LOD) of 1.69mUmL. This approach is applicable for the visual detection of β-Gal activities in the presence of complex human serum samples. Besides, when integrated with the sandwich immunoassay of carcinoembryonic antigen, a LOD of 1.16ngmL can be achieved. In light of its prominent simplicity and practicality, our MLCT-based approach holds great potential in diagnostic and analytical applications.
在这项工作中，我们报告了显色剂 Fe（BPDS）（BPDS=联苯二磺酸钠）报告分子独特的金属-配体电荷转移（MLCT）吸收特性的一种新用途，用于β-半乳糖苷酶（β-Gal）活性和三明治免疫测定的可视化检测。通过酶解底物对氨基苯-β-D-半乳糖吡喃糖苷，可以打开 Fe 还原为 Fe 的过程，随后 Fe 与 BPDS 配体络合生成报告分子 Fe（BPDS），导致在 535nm 处出现强 MLCT 吸收带，溶液颜色从无色变为红色。通过单一步骤，可以在 0-220mUmL 的动态范围内灵敏且选择性地检测β-Gal 的活性，检测限（LOD）为 1.69mUmL。该方法适用于在复杂的人血清样本中存在时可视化检测β-Gal 活性。此外，当与癌胚抗原的三明治免疫测定结合使用时，可以达到 1.16ngmL 的 LOD。鉴于其突出的简单性和实用性，我们基于 MLCT 的方法在诊断和分析应用中具有很大的潜力。
