title: In situ DNA amplification with magnetic primers for the electrochemical detection of food pathogens.
abstract: A sensitive and selective genomagnetic assay for the electrochemical detection of food pathogens based on in situ DNA amplification with magnetic primers has been designed. The performance of the genomagnetic assay was firstly demonstrated for a DNA synthetic target by its double-hybridization with both a digoxigenin probe and a biotinylated capture probe, and further binding to streptavidin-modified magnetic beads. The DNA sandwiched target bound on the magnetic beads is then separated by using a magneto electrode based on graphite-epoxy composite. The electrochemical detection is finally achieved by an enzyme marker, anti-digoxigenin horseradish peroxidase (HRP). The novel strategy was used for the rapid and sensitive detection of polymerase chain reaction (PCR) amplified samples. Promising resultants were also achieved for the DNA amplification directly performed on magnetic beads by using a novel magnetic primer, i.e., the up PCR primer bound to magnetic beads. Moreover, the magneto DNA biosensing assay was able to detect changes at single nucleotide polymorphism (SNP) level, when stringent hybridization conditions were used. The reliability of the assay was tested for Salmonella spp., the most important pathogen affecting food safety.
authors.affiliation: Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Lermo
authors.forename: S
authors.initials: S
authors.lastname: Campoy
authors.forename: J
authors.initials: J
authors.lastname: Barbé
authors.forename: S
authors.initials: S
authors.lastname: Hernández
authors.forename: S
authors.initials: S
authors.lastname: Alegret
authors.forename: M I
authors.initials: MI
authors.lastname: Pividori
mesh_terms: D015374:Biosensing Techniques; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis*; D004563:Electrochemistry; D005516:Food Microbiology; D008280:Magnetics; D016133:Polymerase Chain Reaction; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial