title: An Electrochemical Immunosensor for Detection of Staphylococcus aureus Bacteria Based on Immobilization of Antibodies on Self-Assembled Monolayers-Functionalized Gold Electrode.
abstract: The detection of pathogenic bacteria remains a challenge for the struggle against biological weapons, nosocomial diseases, and for food safety. In this research, our aim was to develop an easy-to-use electrochemical immunosensor for the detection of pathogenic Staphylococcus aureus ATCC25923. The biosensor was elaborated by the immobilization of anti-S. aureus antibodies using a self-assembled monolayer (SAMs) of 3-Mercaptopropionic acid (MPA). These molecular assemblies were spontaneously formed by the immersion of the substrate in an organic solvent containing the SAMs that can covalently bond to the gold surface. The functionalization of the immunosensor was characterized using two electrochemical techniques: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Here, the analysis was performed in phosphate buffer with ferro/ferricyanide as the redox probe. The EIS technique was used for affinity assays: antibody-cell binding. A linear relationship between the increment in the electron transfer resistance (RCT) and the logarithmic value of S. aureus concentration was observed between 10 and 106 CFU/mL. The limit of detection (LOD) was observed at 10 CFU/mL, and the reproducibility was calculated to 8%. Finally, a good selectivity versus E. coli and S. epidermidis was obtained for our developed immunosensor demonstrating its specificity towards only S. aureus.
authors.affiliation: Laboratoire de Physique et Chimie des Interfaces, Faculté des Sciences de Monastir, Tunisie, Avenue de l'Environnement, 5019 Monastir, Tunisia. mohamed_braiek@yahoo.fr.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Braiek
authors.affiliation: Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie de Monastir, Rue Avicenne 5000, Monastir, Tunisia. karima_rokbani@yahoo.fr.
authors.forename: Karima Bekir
authors.initials: KB
authors.lastname: Rokbani
authors.affiliation: Laboratoire de Physique et Chimie des Interfaces, Faculté des Sciences de Monastir, Tunisie, Avenue de l'Environnement, 5019 Monastir, Tunisia. amani.chrouda@yahoo.fr.
authors.forename: Amani
authors.initials: A
authors.lastname: Chrouda
authors.affiliation: Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie de Monastir, Rue Avicenne 5000, Monastir, Tunisia. mrabetbechir@yahoo.fr.
authors.forename: Béchir
authors.initials: B
authors.lastname: Mrabet
authors.affiliation: Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie de Monastir, Rue Avicenne 5000, Monastir, Tunisia. aminafdhila@yahoo.fr.
authors.forename: Amina
authors.initials: A
authors.lastname: Bakhrouf
authors.affiliation: Laboratoire de Physique et Chimie des Interfaces, Faculté des Sciences de Monastir, Tunisie, Avenue de l'Environnement, 5019 Monastir, Tunisia. abderrazak.maaref@fsm.rnu.tn.
authors.forename: Abderrazak
authors.initials: A
authors.lastname: Maaref
authors.affiliation: Institut des Sciences Analytiques, UMR CNRS 5280, Université Claude Bernard-Lyon1, Bâtiment CPE, 69622 Villeurbanne Cedex, France. nicole.jaffrezic@univ-lyon1.fr.
authors.forename: Nicole
authors.initials: N
authors.lastname: Jaffrezic-Renault