Impedance Based Biosensor for Agricultural Pathogen Detection

One of the major limitations on food resources worldwide is the deterioration of plant products due to pathogenic infections. Early screening of plants for pathogenic infections can serve as a boon in the Agricultural sector. The standard microbiology techniques have not kept pace with the rapid enumeration and automated methods for bacteria detection. Electrochemical impedance spectroscopy (EIS) serves as a label free bio sensing technique to monitor pathogens in real time. The changes in the electrical-impedance of a growing bacterial culture can be monitored to detect activity of microorganisms. In this study, we demonstrate development of a gold interdigitated electrode (gold IDE) based impedance biosensor to detect bacterial cell enrichment in a growth medium. To standardize the impedance measurement protocol, nutrient broth suspended E.coli cells were used as a model system. The changes in the magnitude of impedance is about 1.5M Omega per doubling of E.coli cells. We further extended this strategy to identify the pathogens in real samples using milk as cell growth medium. Distinct difference of about 5M Omega was seen in the impedance recorded for the healthy and infected potato samples. Our results support the potential application of this impedance based biosensor in agricultural pathogen detection