Aptamer-based nanobiosensors for the detection of E.coli

Background and Aim : Escherichia coli (E.coli) is a pathogenic bacterium that is transmitted tohumans through food. There are many conventional methods for detecting the presence of E. coli,which usually take two to three days. But nanotechnology and new methods have made thisdiagnosis easier. A simple, fast and environmentally friendly method to detect this pathogen isusing aptamer-based nanobiosensors. Aptamers refer to single-stranded nucleic acids (singlestrandedDNA or RNA) or oligopeptides capable of binding to a target specifically with highaffinity.Methods : Keywords of aptasensor, nanobiosensor and E.coli were searched in PubMed andGoogle Scholar databases between ۲۰۰۹ until ۲۰۲۲.Results : Aptamer-based optical sensors, including visible light, ultraviolet, and fluorescentsensors, have been developed and widely used. Compared with visual detection and colorimetry,E.coli aptasensors based on fluorescence measurement have many advantages of the opinion ofdetection sensitivity, feature selection, etc.. In the construction of a aptasensor, the target E.coliwas captured by antibody-conjugated magnetic beads. Second, RNA aptamers were sandwichedonto the surface of captured E.coli. Finally, heat-released aptamers were amplified using real-timereverse transcription-PCR (RT-PCR). Developed aptamer-based biosensors (aptasensors) basedon label-free aptamers and gold nanoparticles (AuNPs) for the detection of E. coli. Aptamersbinding to target bacteria are adsorbed on the surface of unmodified AuNPs to attract targetbacteria, and detection was performed by aggregation of the aptasensor induced by target bacteria,which is correlated as a red-to-purple color change under high-salt conditions. This aptasensorcould detect less than ۱۰۵ colonies forming units (CFU)/mL of the target bacteria in ۲۰ min orless, and the specificity was ۱۰۰%.Conclusion : This review presents new developments in the development of aptamer-basedsensors for the diagnosis and treatment of E.coli. Due to the current limitations of commondetection techniques in the early diagnosis of infectious diseases, researchers have turned theirattention to the development of aptamer-based diagnostics for rapid and efficient non-invasivediagnosis of diseases. Aptamer-based biosensors are gaining importance due to their manyadvantages over other biosensors. However, the development of biosensors for the diagnosis ofseveral diseases is still a great challenge for scientists and researchers.

کلیدواژه ها:

aptasensor ، nanobiosensor ، Escherichia Coli