Platform Formed from ZIF‑8 and DNAzyme: “Turn-On” Fluorescence Assay for Simple, High-Sensitivity, and High-Selectivity Detection of Pb2

• Published in: Journal of agricultural and food chemistry Vol. 70; no. 30; pp. 9567 - 9576
• Main Authors: Yang, Chuanyu, Yu, Peitong, Li, Ying, Wang, Junyang, Ma, Xinyue, Liu, Ni, Lv, Ting, Zheng, Hongru, Wu, Han, Li, Hongxia, Sun, Chunyan
• Format: Journal Article
• Language: English
• Published: American Chemical Society 03.08.2022
• Subjects: New Analytical Methods; DNAzyme; ZIF-8; MOF; lead detection; fluorescence sensor
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.2c03503

Lead contamination has posed a potential threat to the environment and food safety, arousing extensive concern. In this work, we fabricated a novel fluorescent sensing platform based on zeolitic imidazolate framework-8 (ZIF-8) and DNAzyme for monitoring Pb2+ in water and fish samples. ZIF-8 was proposed as a fluorescence quencher with the advantages of simple synthesis, low cost, and high quenching efficiency. The Pb2+-dependent GR5 DNAzyme containing the large ssDNA loop can be adsorbed onto ZIF-8 accompanied by fluorescence quenching. Upon binding with Pb2+, GR5 DNAzyme was activated and cleaved, leading to the release of FAM-labeled 5-base ssDNA, which restored the fluorescence. The “turn-on” assay can detect Pb2+ through the one-pot procedure in the range of 0.01–10.0 nM with a detection limit of 7.1 pM. The platform is promising for on-site monitoring of Pb2+ owing to the excellent performance of high sensitivity, low background, strong anti-interference ability, and simple operation.