RETRACTED ARTICLE: A fluorescent Zn(II)-organic framework for selective detection of Pb2+ and a protective effect in osteoarthritis treatment by reducing ROS accumulation and apoptosis in chondrocytes

By using the π-electron rich 4,4′-stilbenedicarboxylic acid (H2sda), a Zn(II)-bearing metal-organic framework with the chemical formula of [Zn3(sda)3(H2O)2](H2O)4 (1) has been prepared through the reaction of the 4,4′-stilbenedicarboxylic acid with Zn(NO3)2·6H2O in the component solvent of H2O and MeOH with aid of HBF4. Considering its intensive fluorescent emission, 1 was studied as a fluorescent sensor for metal ions in water, and the results reveal that 1 can be developed into an excellent Pb2+ sensor in water by utilizing luminescence quenching with a detection limit of 32.6 nm. In biological research, we explored the protective effect of 1 in OA rats. First, the DCFH-DA staining assay was utilized to detect the ROS levels in primary chondrocyte. Then, the Annexin V-FITC/PI was conducted for evaluating the apoptotic cells percentage after treatment with 1. The results from molecular docking software exhibited a possible mode of the compound binding to Bcl2, indicating a potential modulation mechanism.