Rapid detection of multiple foodborne pathogens using a nanoparticle-functionalized multi-junction biosensor.

Real-time identification of multiple bacterial pathogens in food is urgently needed to ensure food safety. Although rapid and sensitive detection methods offering simplicity, accuracy, and multiplexity are highly desirable for industrial food applications, the development of a biosensor that meets all criteria remains a challenge. In this study, a single walled carbon nanotube- (SWCNT) based multi-junction sensor was designed for potential multiplexed detection of foodborne pathogens.

Single walled carbon nanotube-based junction biosensor for detection of Escherichia coli.

Foodborne pathogen detection using biomolecules and nanomaterials may lead to platforms for rapid and simple electronic biosensing. Integration of single walled carbon nanotubes (SWCNTs) and immobilized antibodies into a disposable bio-nano combinatorial junction sensor was fabricated for detection of Escherichia coli K-12. Gold tungsten wires (50 µm diameter) coated with polyethylenimine (PEI) and SWCNTs were aligned to form a crossbar junction, which was functionalized with streptavidin and biotinylated antibodies to allow for enhanced specificity towards targeted microbes.

Electrochemical impedance spectroscopic technique with a functionalized microwire sensor for rapid detection of foodborne pathogens.

In this study, a label-free biosensor based on electrochemical impedance measurement followed by dielectrophoretic force and antibody-antigen interaction was developed for detection and quantification of foodborne pathogenic bacteria. In our previous work, gold-tungsten wires (25 μm in diameter) were functionalized by coating with polyethyleneimine-streptavidin-anti-Escherichia coli antibodies to improve sensing specificity, and fluorescence intensity measurement was employed to quantify bacteria captured by the sensor. The focus of this research is to evaluate the performance of the developed biosensor by monitoring the changes of electron-transfer resistance (ΔR(et)) of the microwire after the bioaffinity reaction between bacterial cells and antibodies on its surface as an alternative quantification technique to fluorescence microscopy.