Fluorescent Aptasensors: Design Strategies and Applications in Analyzing Chemical Contamination of Food

Abstract

C aused by various factors, including planting, breeding, production, processing, packaging, and environmental pollution, most food is inevitably contaminated at a certain degree by common chemical substances, such as pesticides, veterinary drugs, toxins, or heavy metals. These substances can have negative effects on human health depending on their

Toward Integrated Molecular Lateral Flow Diagnostic Tests Using Advanced Micro- and Nanotechnology

“…Aptamers are single-stranded DNA (ssDNA) or single-stranded RNA (ssRNA) molecules that fold in a complex 2D or 3D structure and bind to a target with high affinity and selectivity. , They have several clear advantages over Ab, including high stability, in vitro generation, ease in functionalization, and capacity for large-scale synthesis. , Aptamers are developed by an in vitro iterative process called “systematic evolution of ligands by exponential enrichment” (SELEX), which has been modified depending on the target of interest. − By SELEX or its variants, aptamers have been generated for hormones; drugs; heavy metals; proteins; toxins; enzymes; cancer cells; and bacterial, viral, and fungal pathogens . Aptamer-based LF tests use aptamers as bioreceptors; however, they do not solve the lack of sensitivity of the LF, and their binding activity is highly dependent on the ionic strength of the buffer and the presence of certain cations …”

Label-Free Fluorescence Sensing Strategy Based on Functional Nucleic Acids via Energy Transfer between DNA-Templated Silver Nanoclusters and Gold Nanorods

“…In recent years, biosensing technologies based on functional nucleic acids (FNAs) have attracted wide attention and shown great potential in the field of chemical contaminant detection in food and the environment. , FNA is a kind of nucleic acid molecule with recognition or catalytic function obtained through screening in vitro, mainly including aptamers, ribozymes, and DNAzymes. Aptamers are single-stranded oligonucleotides selected from a set of DNA or RNA through the standard process of exponential enrichment of the systematic evolution of ligands by exponential enrichment (SELEX) .…”

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

“…Therefore, DNAzyme-based biosensors have been developed by multiple signal formats, including electrochemistry, fluorometry, and colorimetry . Among them, fluorescence biosensors display outstanding properties of high sensitivity, simple operation, rapid detection, and low cost . In this work, a novel fluorescence strategy for Pb 2+ detection was developed using GR5 DNAzyme as the catalytic unit, and zeolitic imidazolate framework-8 (ZIF-8) as the efficient fluorescence quencher.…”