title: Electrochemical Genosensor To Detect Pathogenic Bacteria (Escherichia coli O157:H7) As Applied in Real Food Samples (Fresh Beef) To Improve Food Safety and Quality Control.
abstract: The electrochemical genosensor is one of the most promising methods for the rapid and reliable detection of pathogenic bacteria. In a previous work, we performed an efficient electrochemical genosensor detection of Staphylococcus aureus by using lead sulfide nanoparticles (PbSNPs). As a continuation of this study, in the present work, the electrochemical genosensor was used to detect Escherichia coli O157:H7. The primer and probes were designed using NCBI database and Sigma-Aldrich primer and probe software. The capture and signalizing probes were modified by thiol (SH) and amine (NH2), respectively. Then, the signalizing probe was connected using cadmium sulfide nanoparticles (CdSNPs), which showed well-defined peaks after electrochemical detection. The genosensor was prepared by immobilization of complementary DNA on the gold electrode surface, which hybridizes with a specific fragment gene from pathogenic to make a sandwich structure. The conductivity and sensitivity of the sensor were increased by using multiwalled carbon nanotubes (MWCNT) that had been modified using chitosan deposited as a thin layer on the glass carbon electrode (GCE) surface, followed by a deposit of bismuth. The peak currents of E. coli O157:H7 correlated in a linear fashion with the concentration of tDNA. The detection limit was 1.97 × 10(-14) M, and the correlation coefficient was 0.989. A poorly defined current response was observed as the negative control and baseline. Our results showed high sensitivity and selectivity of the electrochemical DNA biosensor to the pathogenic bacteria E. coli O157:H7. The biosensor was also used to evaluate the detection of pathogen in real beef samples contaminated artificially. Compared with other electrochemical DNA biosensors, we conclude that this genosensor provides for very efficient detection of pathogenic bacteria. Therefore, this method may have potential application in food safety and related fields.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Wuxi, Jiangsu 214122, China.
authors.forename: Mandour H
authors.initials: MH
authors.lastname: Abdalhai
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Wuxi, Jiangsu 214122, China.
authors.forename: António Maximiano
authors.initials: AM
authors.lastname: Fernandes
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Wuxi, Jiangsu 214122, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Wuxi, Jiangsu 214122, China.
authors.forename: Abubakr
authors.initials: A
authors.lastname: Musa
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Wuxi, Jiangsu 214122, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Wuxi, Jiangsu 214122, China.
authors.forename: Xiulan
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D002417:Cattle; D055664:Electrochemical Techniques / Q000379:methods*; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis*; D059022:Food Safety; D011786:Quality Control; D000069466:Red Meat / Q000382:microbiology*
keywords: E. coli O157:H7; beef sample; cadmium sulfide nanoparticle; electrochemical genosensor; sandwich structure