Ratiometric Fluorescence Assay for Pyrophosphate Based on Sulfur Nanodots Decorated Metal‐Organic Frameworks

Abstract

AbstractSelective and sensitive detection of inorganic pyrophosphate (PPi) are of great significance both for clinical applications and fundamental research. In this work, a ratiometric fluorescent probe was developed by decorating a porphyrin‐based metal‐organic framework (PCN‐224) with sulfur nanodots (S‐dots). The red‐fluorescence of PCN‐224 was significantly promoted (more than 6‐fold) by S‐dots through inhibiting molecular motion of porphyrin ligand, which also provided active sites for the detection of Cu2+ and PPi. Cu2+ could selectively quench the red‐fluorescence of PCN‐224 through coordination with porphyrin ligand, and the competition reaction between PPi and Cu2+ resulted in the decomposing of coordination and recovery of red‐fluorescence. The blue‐fluorescence from S‐dots was deemed as effective reference, which provided a built‐in correction in complex environments. Based on these photophysical properties, a ratiometric fluorescence assay was developed for the quantitative detection of Cu2+ and PPi, with a limit of detection of 0.11 and 2.66 μM, respectively. The accuracy and practical applications of assays were also demonstrated by detection in tap water and human serum samples.