title: Salmonella typhimurium detection using a surface-enhanced Raman scattering-based aptasensor.
abstract: Surface-enhanced Raman spectroscopy (SERS) has been used in a variety of biological applications due to its high sensitivity and specificity. Here, we report a SERS-based aptasensor approach for quantitative detection of pathogenic bacteria. A SERS substrate bearing Au@Ag core/shell nanoparticles (NPs) is functionalized with aptamer 1 (apt 1) for the capture of target molecules. X-rhodamine (ROX)-modified aptamer 2 (apt 2) is used as recognition element and Raman reporter. Salmonella typhimurium specifically interacted with the aptamers to form Au@Ag-apt 1-target-apt 2-ROX sandwich-like complexes. As a result, the concentration of S. typhimurium was determined using this developed aptasensor structure, and a calibration curve is obtained in the range of 15 to 1.5 × 10(6) cfu/mL with a limit of detection of 15 cfu/mL. Our method was successfully applied to real food samples, and the results are consistent with the results obtained using plate counting methods. We believe that the developed method shows potential for the rapid and sensitive detection of pathogenic bacteria in food safety assurance.
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Nuo
authors.initials: N
authors.lastname: Duan
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Boya
authors.initials: B
authors.lastname: Chang
authors.affiliation: China Rural Technology Development Center, Beijing 100045, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Zhouping
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China. Electronic address: wusj1986@163.com.
authors.forename: Shijia
authors.initials: S
authors.lastname: Wu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D005516:Food Microbiology / Q000379:methods*; D059022:Food Safety / Q000379:methods; D005517:Foodborne Diseases / Q000382:microbiology / Q000517:prevention & control*; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles; D012486:Salmonella typhimurium / Q000302:isolation & purification*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold
keywords: Aptamer; Au@Ag core/shell NPs; S. typhimurium; SERS