Design of a real time biorecognition system to detect foodborne pathogens-DNA biosensor

Abstract

In recent years, there has been numerous research papers reported on the use of DNA biosensors for the detection of foodborne pathogens. However, none of the papers to date reflect the detection of foodborne pathogens directly in food using a handheld DNA biosensor. It has been shown in our recent work that DNA sequences named BCFomp1/BCRomp1 can be used for the specific detection of the Bacillus cereus (B. cereus) group species (spp). Analysis of these DNA probes using standard PCR analysis showed that the minimum level of detection was 10 ³ CFU/ml. The lowest number of bacterial cell per reaction tube that can be amplified was 5 CFU and the minimum quantity of DNA that can be amplified was found to be 1pg. The prime intention of this paper was to pioneer the design and fabrication of a single-strand (ss) DNA biosensor for the detection of the B. cereus group spp. Cyclic voltammetry (CV) was used to develop and test a model DNA-based biosensor. The electrically conducting polymer, polypyrrole was used as a platform for immobilizing DNA on the gold electrode surface. The model DNA biosensor generated unique CV signals between complementary and noncomplementary oligonucleotides and it proved to be effective.