title: Sensitive electrochemical detection of Salmonella with chitosan-gold nanoparticles composite film.
abstract: An ultrasensitive electrochemical immunosensor for detection of Salmonella has been developed based on using high density gold nanoparticles (GNPs) well dispersed in chitosan hydrogel and modified glassy carbon electrode. The composite film has been oxidized in NaCl solution and used as a platform for the immobilization of capture antibody (Ab1) for biorecognition. After incubation in Salmonella suspension and horseradish peroxidase (HRP) conjugated secondary antibody (Ab2) solution, a sandwich electrochemical immunosensor has been constructed. The electrochemical signal was obtained and improved by comparing the composite film with chitosan film. The result has shown that the constructed sensor provides a wide linear range from 10 to 10(5) CFU/mL with a low detection limit of 5 CFU/mL (at the ratio of signal to noise, S/N=3:1). Furthermore, the proposed immunosensor has demonstrated good selectivity and reproducibility, which indicates its potential in the clinical diagnosis of Salmonella contaminations.
authors.affiliation: Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, PR China; Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Canada M1C 1A4.
authors.forename: Cuili
authors.initials: C
authors.lastname: Xiang
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Canada M1C 1A4.
authors.forename: Ran
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Canada M1C 1A4.
authors.forename: Bimalendu
authors.initials: B
authors.lastname: Adhikari
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Canada M1C 1A4.
authors.forename: Zhe
authors.initials: Z
authors.lastname: She
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Canada M1C 1A4; Department of Sanitary Chemistry, Public Health School, West China Medical Center, Sichuan University, Chengdu 610044, PR China.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Canada M1C 1A4; Department of Chemistry, University of Toronto, Toronto, Canada M5S 3H6. Electronic address: bernie.kraatz@utoronto.ca.
authors.forename: Heinz-Bernhard
authors.initials: HB
authors.lastname: Kraatz
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation; D048271:Chitosan / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008892:Milk / Q000382:microbiology; D015203:Reproducibility of Results; D012475:Salmonella / Q000302:isolation & purification*; D012480:Salmonella Infections / Q000382:microbiology*; D014871:Water Microbiology
chemical_list: D006046:Gold; D048271:Chitosan
keywords: Chitosan; Composite film; Electrochemical immunosensor; Gold nanoparticles; Salmonella