Shu Tong, Sun Yanping, Bai Yunlong, Lin Xiangfang, Zhou Ziping, Su Lei, Zhang Xueji
Beijing Key Laboratory for Bioengineering and Sensing Technology, Research Center for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, China.
ACS Omega. 2020 Apr 9;5(15):8943-8951. doi: 10.1021/acsomega.0c00711. eCollection 2020 Apr 21.
Recently, multiplexed ratiometric fluorescence sensors for detecting several analytes have received much interest because of their multifunctionality. Here, we fabricate a novel trinity fluorescent nanoprobe in which one small-molecule fluorophore, blue-emissive dityrosine (diTyr) residues, and two nanomaterial fluorophores, green-emissive CdS quantum dots (CdSQDs) and red-emissive gold nanoclusters (AuNCs), are cocaged in a bovine serum albumin (BSA) molecule. The large differences of Stokes shifts among diTyr residues, CdSQDs, and AuNCs ensure their emission at a single excitation wavelength. The nanoprobes can be facilely integrated using two-step synthetic reactions. DiTyr residues and AuNCs are formed and bound to the protein cage through the redox reaction between Au and tyrosine residues of BSA, and the CdSQDs are followed to be conjugated to the modified BSA cage-templated CdS combination reaction. With established benign biocompatibility, the nanoprobes can ratiometrically detect intracellular glutathione by significantly enhancing the green emission of the conjugated CdSQDs. Likewise, the ratiometric sensing of solution alkalinity and tris(2-carboxyethyl)phosphine can be achieved using blue-emitted diTyr residues and red-emitted AuNCs as the responsive units, respectively, and the corresponding other two fluorophores as the reference signals. This study addresses a concept of trinity fluorescence ratiometric sensing system with multiple targets and optional references, which should be a promising pathway to meet the challenges from complexing biochemical environments and multivariate analysis.
近年来，用于检测多种分析物的多路复用比率荧光传感器因其多功能性而备受关注。在此，我们制备了一种新型的三位一体荧光纳米探针，其中一个小分子荧光团、蓝色发射的二酪氨酸（diTyr）残基以及两个纳米材料荧光团，即绿色发射的硫化镉量子点（CdSQDs）和红色发射的金纳米簇（AuNCs），被共包封在牛血清白蛋白（BSA）分子中。diTyr残基、CdSQDs和AuNCs之间斯托克斯位移的巨大差异确保了它们在单一激发波长下发射。该纳米探针可通过两步合成反应轻松整合。通过金与BSA的酪氨酸残基之间的氧化还原反应形成diTyr残基和AuNCs并将它们结合到蛋白质笼中，随后通过修饰的BSA笼模板化的CdS复合反应将CdSQDs共轭到其上。凭借已确立的良好生物相容性，该纳米探针可以通过显著增强共轭CdSQDs的绿色发射来比率检测细胞内谷胱甘肽。同样，分别使用蓝色发射的diTyr残基和红色发射的AuNCs作为响应单元，以及相应的其他两种荧光团作为参考信号，可以实现对溶液碱度和三（2 - 羧乙基）膦的比率传感。本研究提出了一种具有多个目标和可选参考的三位一体荧光比率传感系统的概念，这应该是应对复杂生化环境和多变量分析挑战的一条有前途的途径。
