In this work, we designed a novel dual-emission reverse change ratio fluorescence nanoplatform for fluorimetric and colorimetric sensing of heparin (Hep) and chondroitin sulfate (CS) based on green emissive terbium metal-organic framework (Tb MOF) and red emissive bovine serum albumin capped gold nanoclusters (BSA@AuNCs). When excess Tb MOF was mixed with BSA@Au NCs, the nanoaggregates of Tb MOF and BSA@Au NCs could be precipitated by centrifugation due to the electrostatic interactions between them, and the supernatant displayed bright green color of Tb MOF under 254 nm UV lamp. However, the introduced Hep or CS caused the decomposition of Tb MOF since Tb³⁺ has stronger affinity with Hep and CS, which resulted in the release of BSA@AuNCs into the supernatant. As a result, the red fluorescence of BSA@Au NCs turned on while the green fluorescence of Tb MOF turned off under the 254 nm UV illumination. The dual- emission reverse change ratio fluorescence nanoplatform possessed the variations of the emission intensity ratio at two different wavelength and the corresponding green-to-red fluorescent color changes, endowing a novel mechanism for fluorimetric and colorimetric analysis of Hep and CS using fluorescence spectrophotometer and smartphone, respectively. With the ratiometric fluorescence nanoprobe, simple and rapid sensing of Hep and CS with high sensitivity, selectivity and accuracy could be realized. Moreover, successful recoveries of the analytes in human serum samples were also validated, indicating promising application for Hep and CS analysis in biomedical diagnosis.

在这项工作中，我们设计了一种基于绿色发光铽金属有机骨架 (Tb MOF) 和红色发光牛血清的新型双发射反向变化比荧光纳米平台，用于肝素 (Hep) 和硫酸软骨素 (CS) 的荧光和比色传感白蛋白封端的金纳米团簇（BSA@AuNCs）。当过量的 Tb MOF 与 BSA@Au NCs 混合时，Tb MOF 和 BSA@Au NCs 的纳米聚集体由于它们之间的静电相互作用可以通过离心沉淀，并且上清液在 254 nm 紫外灯下显示出 Tb MOF 的亮绿色. 然而，引入的 Hep 或 CS 引起了 Tb MOF 的分解，因为 Tb ³⁺与 Hep 和 CS 有更强的亲和力，导致 BSA@AuNCs 释放到上清液中。因此，在 254 nm 紫外光照射下，BSA@Au NCs 的红色荧光开启，而 Tb MOF 的绿色荧光关闭。双发射反向变化比荧光纳米平台具有两种不同波长下发射强度比的变化和相应的绿色到红色荧光颜色变化，为使用荧光分光光度计和 CS 的荧光和比色分析提供了一种新的机制。智能手机，分别。使用比例荧光纳米探针，可以实现简单、快速、高灵敏度、高选择性和高准确度的 Hep 和 CS 检测。此外，还验证了人血清样品中分析物的成功回收率，