AlkalineHydrolysis Behavior of Metal–OrganicFrameworks NH 2 ‑MIL-53(Al) Employed for SensitiveImmunoassay via Releasing Fluorescent Molecules

Nanosized metal–organic frameworks (MOFs) NH2-MIL-53(Al) were synthesized from 2-aminoterephthalic acid (NH2·H2BDC) and AlCl3 by a facile hydrothermal method. The synthesized MOFs displayed good stability and a uniform particle size in a netural medium and were hydrolyzed in alkaline medium to release a large amount of fluorescent ligand NH2·H2BDC. Therefore, they can act as large-capability nanovehicles to load signal molecules for investigating various biorecognition events. In this work, based on the alkaline hydrolysis behavior of MOFs NH2-MIL-53(Al), a sensitive immunoassay method was developed for the detection of aflatoxin B1 (AFB1) by employing them as fluorescent signal probes. With a competitive immunoassay mode on microplate, AFB1 can be detected within a linear range of 0.05–25 ng mL–1. The method was successfully employed to detect AFB1 spiked in Job tears, Polygala tenuifolia and with acceptable recovery values of 83.00–114.00%. The detection results for moldy Fructus xanthii displayed an ac...