title: Colorimetric detection of Escherichia coli O157:H7 using functionalized Au@Pt nanoparticles as peroxidase mimetics.
abstract: The presence of Escherichia coli (E. coli) in food and drinking water is a chronic problem worldwide. Protecting food against bacterial contamination and rapid diagnosis of infection require simple and rapid assays for detection of bacterial pathogens, including E. coli O157:H7. Here we report a rapid and novel colorimetric method for detecting E. coli O157:H7. This colorimetric method is based on the catalytic oxidation of the peroxidase substrate 3,3,5,5-tetramethylbenzidine by hydrogen peroxide using 4-mercaptophenylboronic acid-functioned Au@Pt nanoparticles adsorbed on the surface of E. coli O157:H7. The assay showed excellent sensitivity both with the naked eye and based on absorbance measurements. The absorbance at 652 nm was proportional to the concentration of E. coli O157:H7 ranging from 7 to 6 × 10(6) cfu mL(-1) with a limit of detection of 7 cfu mL(-1). The total detection time was less than 40 min.
authors.affiliation: College of Chemistry and Material Science, Shandong Agricultural University, Taian, 271018, Shandong, China.
authors.forename: Haichao
authors.initials: H
authors.lastname: Su
authors.forename: Han
authors.initials: H
authors.lastname: Zhao
authors.forename: Fengmin
authors.initials: F
authors.lastname: Qiao
authors.forename: Lijian
authors.initials: L
authors.lastname: Chen
authors.forename: Ruihuan
authors.initials: R
authors.lastname: Duan
authors.forename: Shiyun
authors.initials: S
authors.lastname: Ai
mesh_terms: D003124:Colorimetry; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry* / Q000378:metabolism; D010984:Platinum / Q000737:chemistry*
chemical_list: D010984:Platinum; D006046:Gold; D009195:Peroxidase