Du Lizhen, Chen Yanjie, Huang Yitian, Yan Shanshan, Zhang Shupei, Dai Hong
College of Chemistry and Material, Fujian Normal University, Fuzhou, 350108, People's Republic of China.
College of Chemical and Material Engineering, Quzhou University, Quzhou, 32400, Zhejiang, China.
Mikrochim Acta. 2023 Mar 3;190(3):108. doi: 10.1007/s00604-023-05689-z.
A fluorescence quenching enhanced immunoassay has been developed to achieve ultrasensitive recognition of human epididymal 4 (HE4) modifying the fluorescence quencher. The carboxymethyl cellulose sodium-functionalized NbC MXene nanocomposite (CMC@MXene) was firstly introduced to quench the fluorescence signal of the luminophore Tb-Norfloxacin coordination polymer nanoparticles (Tb-NFX CPNPs). The NbC MXene nanocomposite as fluorescent nanoquencher inhibits the electron transfer between Tb and NFX to quench the fluorescent signal by coordinating the strongly electronegative carboxyl group on CMC with Tb (III) of Tb-NFX complex. Simultaneously, due to the superior photothermal conversion capability of CMC@MXene, the fluorescence signal has been further weakened by the photothermal effect driven non-radiative decay of the excited state under near-infrared laser irradiation. The constructed fluorescent biosensor based on CMC@MXene probe finally realized the enhanced fluorescence quenching effect, and achieved ultra-high sensitivity and selective detection of HE4, exhibiting a wide linear relationship with HE4 concentration on the logarithmic axis in the range of 10 to 10 ng/mL and a low detection limit of 3.3 fg/mL (S/N = 3). This work not only provides an enhanced fluorescent signal quenching method for the detection of HE4, but also provides novel insights for the design of fluorescent sensor toward different biomolecules.
已开发出一种荧光猝灭增强免疫分析法，通过修饰荧光猝灭剂实现对人附睾蛋白4（HE4）的超灵敏识别。首先引入羧甲基纤维素钠功能化的NbC MXene纳米复合材料（CMC@MXene）来猝灭发光体铽-诺氟沙星配位聚合物纳米颗粒（Tb-NFX CPNPs）的荧光信号。作为荧光纳米猝灭剂的NbC MXene纳米复合材料通过使CMC上的强电负性羧基与Tb-NFX络合物的Tb（III）配位，抑制Tb与NFX之间的电子转移，从而猝灭荧光信号。同时，由于CMC@MXene具有优异的光热转换能力，在近红外激光照射下，光热效应驱动的激发态非辐射衰变进一步削弱了荧光信号。基于CMC@MXene探针构建的荧光生物传感器最终实现了增强的荧光猝灭效果，实现了对HE4的超高灵敏度和选择性检测，在10至10 ng/mL范围内，与HE4浓度在对数轴上呈现出较宽的线性关系，检测限低至3.3 fg/mL（S/N = 3）。这项工作不仅为HE4的检测提供了一种增强的荧光信号猝灭方法，也为针对不同生物分子的荧光传感器设计提供了新的思路。
