Highly adaptable and sensitive FRET-based aptamer assay for the detection of Salmonella paratyphi A

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 243; p. 118662
• Main Authors: RM, Renuka, Maroli, Nikhil, J, Achuth, Ponmalai, Kolandaivel, K, Kadirvelu
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15-12-2020
• Subjects: Aptamers, Nucleotide; Biosensing Techniques; CdTe quantum dots (QDs); Enzyme Linked Aptamer Sandwich Assay (ELASA); Fluorescence aptasensor; Fluorescence Resonance Energy Transfer; Graphene oxide (GO); Quantum Dots; Reproducibility of Results; Salmonella paratyphi A; ssDNA Aptamers; Salmonella paratyphi A; Graphene oxide (GO); Fluorescence aptasensor; CdTe quantum dots (QDs); ssDNA Aptamers; Enzyme Linked Aptamer Sandwich Assay (ELASA)
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2020.118662

Here we demonstrate a facile and versatile fluorescence resonance energy transfer (FRET) based aptasensor for rapid detection of Salmonella paratyphi A. The assay shows a detection limit up to 10 cfu·mL−1 with no cross-reactivity with other bacterial species. Less than 8% of inter-assay coefficient variance and recovery rate between 85 and 102% attests the assay reliability. The advantages of FRET-based aptamer assay over the conventional immunoassay formats such as ELISA are the specificity, speed, reliability, and simplicity of the assay. The ssDNA aptamers specific towards pathogenic Salmonella paratyphi A were generated via whole-cell SELEX. The aptamer was conjugated onto quantum dot (QD) that served as the molecular beacon and graphene oxide (GO) was used as a fluorescence quencher. Thus the proposed method enables detection of target pathogen using FRET-based assay. Further interaction of aptamer with pathogen protein DNA gyrase was explored using classical molecular dynamics simulation.
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•An aptamer based FRET assay is developed for the determination of Salmonella paratyphi A.•Developed method in combination with Graphene oxide offers rapid and sensitive detection from complex medium.•The detection limit of the proposed method was observed about 10 CFU/mL within 15 min.•Specificity of aptamer was determined by molecular simulation.