title: High Specific DNAzyme-Aptamer Sensor for Salmonella paratyphi A Using Single-Walled Nanotubes-Based Dual Fluorescence-Spectrophotometric Methods.
abstract: In this work, single-stranded DNA aptamers that are highly specific to enterotoxigenic Salmonella paratyphi A were obtained from an enriched oligonucleotide pool using Systematic Evolution of Ligands by Exponential Enrichment (SELEX) to target the flagellin protein. The selected aptamers were confirmed to have high sensitivity and specificity to the flagellin. In addition, a probe (P0) containing the DNAzyme and fluorescein isothiocyanate-labeled aptamer3 sequences was employed as a dual probe for observing fluorescence and absorbance changes. The flagellin demonstrated low detection limits of 5 ng/mL by fluorescence and 20 ng/mL by spectrophotometry. Moreover, milk samples spiked with Salmonella paratyphi A were also detected, with the low detection limits increasing to 10(5) CFU/mL by fluorescence and 10(6)CFU/mL by spectrophotometry. The combination of fluorescence and spectrophotometry offers a specific, rapid, and sensitive way for detecting Salmonella paratyphi A and has potential for detecting other pathogens in food.
authors.affiliation: Hunan Normal University, Changsha, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ning
authors.affiliation: Hunan Normal University, Changsha, China.
authors.forename: WenKai
authors.initials: W
authors.lastname: Li
authors.affiliation: Hunan Normal University, Changsha, China.
authors.forename: YingFen
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Hunan Normal University, Changsha, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.affiliation: Hunan Normal University, Changsha, China denglehunnu@163.com dengle@hunnu.edu.cn.
authors.forename: Le
authors.initials: L
authors.lastname: Deng
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D002138:Calibration; D015169:Colony Count, Microbial; D021881:DNA, Catalytic / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D005408:Flagellin / Q000737:chemistry; D016650:Fluorescein-5-isothiocyanate; D005453:Fluorescence; D005516:Food Microbiology; D006427:Hemin / Q000737:chemistry; D008892:Milk / Q000382:microbiology; D043942:Nanotubes / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry; D052156:SELEX Aptamer Technique; D012482:Salmonella paratyphi A / Q000302:isolation & purification*; D013050:Spectrometry, Fluorescence
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D005408:Flagellin; D006427:Hemin; D016650:Fluorescein-5-isothiocyanate
keywords: DNAzyme; SELEX; Salmonella paratyphi A; flagellin; single-walled nanotubes