title: Aptasensors for rapid detection of Escherichia coli O157:H7 and Salmonella typhimurium.
abstract: Herein we reported the development of aptamer-based biosensors (aptasensors) based on label-free aptamers and gold nanoparticles (AuNPs) for detection of Escherichia coli (E. coli) O157:H7 and Salmonella typhimurium. Target bacteria binding aptamers are adsorbed on the surface of unmodified AuNPs to capture target bacteria, and the detection was accomplished by target bacteria-induced aggregation of the aptasensor which is associated as red-to-purple color change upon high-salt conditions. By employing anti-E. coli O157:H7 aptamer and anti-S. typhimurium aptamer, we developed a convenient and rapid approach that could selectively detect bacteria without specialized instrumentation and pretreatment steps such as cell lysis. The aptasensor could detect as low as 105colony-forming units (CFU)/ml target bacteria within 20 min or less and its specificity was 100%. This novel method has a great potential application in rapid detection of bacteria in the near future.
authors.affiliation: Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, Zhejiang, 325035, China. qum209@mail.usask.ca.
authors.forename: Wen-He
authors.initials: WH
authors.lastname: Wu
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Hou-Xian
authors.initials: HX
authors.lastname: Ouyang
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Ci-Xiu
authors.initials: CX
authors.lastname: Li
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Cao
authors.forename: Qing-He
authors.initials: QH
authors.lastname: Meng
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Lu