Detection of Pb2+ in Tea Using Aptamer Labeled with AIEgen Nanospheres Based on MOFs Sensors

Abstract

Tea is an important economic crop and health beverage in China. The presence of heavy metal ions in tea poses a significant threat to public health. Here, we prepared an aptamer biosensor labelled with AIEgen nanospheres to detect Pb2+ in tea. The dsDNA modified by amino and phosphoric acid was combined with the carboxylated AIEgen NPs to form AIEgen-DNA with a fluorescence group, which was then fixed to the surface of Zr-MOFs to quench the fluorescence of AIEgen NPs. At the same time, PEG was added to remove nonspecific adsorption. Then Pb2+ was added to cut the DNA sequences containing the cutting sites, and AIEgen NPs and part of the DNA sequences were separated from the Zr-MOFs surface to recover the fluorescence. By comparing the fluorescence changes before and after adding Pb2+, the detection limit of Pb2+ can reach 1.70 nM. The fluorescence sensor was applied to detect Pb2+ in tea, and the detection results showed that the tea purchased on the market did not contain the concentration of Pb2+ within the detection range. This study provides new insights into monitoring food and agriculture-related pollutants based on fluorescent biosensors.

Surface ligand-assisted synthesis and biomedical applications of metal–organic framework nanocomposites

“…10A). 140 Such a nanocomposite exhibited high sensitivity and selectivity to Pb 2+ , holding great promise for applications in food safety and environmental analysis. These works offered an efficient strategy for the target-responsive and controllable assembly of MOF nanocomposites, holding great promise for applications in biosensing and stimuli-induced therapy.…”

“…For example, Gao et al utilized Pb 2+ -responsive double-stranded DNA to assemble a MOF/ AIEgen nanoprobe for the highly sensitive detection of Pb 2+ . 140 MOFs can quench the fluorescence of AIEgen through FRET. However, in the presence of Pb 2+ , the double-stranded DNA would be cleaved, and consequently, MOFs and AIEgen would separate, leading to the fluorescence recovery of AIEgen.…”

Recent Advances in the Application of Bionanosensors for the Analysis of Heavy Metals in Aquatic Environments

“…Copyright 2020, RSC advances. ( d ) Schematic diagram of AIEgen nanosphere-labeled aptamer combined with Zr-MOFs for detection of Pb 2+ , TEM image of AIEgen NPs and TEM image of MOF [ 67 ]. Reprinted with permission [ 67 ].…”

“…To luminesce, AIEgen NPS and certain DNA sequences were extracted from the surface of Zr-MOFs. The concentration of Pb 2+ was determined by comparing the fluorescence changes before and after the addition of Pb 2+ [67]. Aptamer/MCH/AuNPs/GCE [64].…”

Construction of a highly efficient DNA nanotube sensor with peroxide-like activity

“…These catalysts offer several advantages, including high efficiency, high selectivity, easy synthesis, and customizable structure. 8 At present, scientists have proficiently employed DNA molecules to fabricate diverse biomimetic catalysts, including DNAzyme, 9 DNA metal–organic frameworks, 10 and DNA-based artificial metalloenzymes. 8 DNA-based artificial metalloenzymes are promising artificial catalysts that combine the advantages of DNA and metal complex catalysts, and they have a wide range of applications in biomedical and chemical synthesis, etc.…”