title: A sensitive gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus.
abstract: In this study, a gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus (S. aureus) using tyramine signal amplification (TSA) technology has been developed. First, the biotinylated aptamer specific for S. aureus was immobilized on the surface of the wells of the microtiter plate via biotin-avidin binding. Then, the target bacteria (S. aureus), biotinylated-aptamer-streptavidin-HRP conjugates, biotinylated tyramine, hydrogen peroxide and avidin-catalase were successively introduced into the wells of the microtiter plate. After that, the existing catalase consumed the hydrogen peroxide. Finally, the freshly prepared gold (III) chloride trihydrate was added, the color of the reaction production would be changed and the absorbance at 550 nm could be measured with a plate reader. Under optimized conditions, there was a linear relationship between the absorbance at 550 nm and the concentration of S. aureus over the range from 10 to 10(6) cfu mL(-1) (with an R² of 0.9947). The limit of the developed method was determined to be 9 cfu mL(-1).
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: Jinglei
authors.initials: J
authors.lastname: Yuan
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: Shijia
authors.initials: S
authors.lastname: Wu
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: Xiaoyuan
authors.initials: X
authors.lastname: Ma
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: Yu
authors.initials: Y
authors.lastname: Xia
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: Jie
authors.initials: J
authors.lastname: Chen
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: Zhansheng
authors.initials: Z
authors.lastname: Ding
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. Electronic address: wangzp@jiangnan.edu.cn.
authors.forename: Zhouping
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D015374:Biosensing Techniques; D019921:Biotinylation; D002374:Catalase / Q000737:chemistry; D003124:Colorimetry; D005516:Food Microbiology / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D014439:Tyramine / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D001426:Bacterial Proteins; C058865:Strep-avidin conjugated horseradish peroxidase; D006046:Gold; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D002374:Catalase; D014439:Tyramine
keywords: Aptamer; Gold nanoparticles; Staphylococcus aureus; Tyramine signal amplification