Capture and Electrochemical Detection of Pathogenic E. coli

Abstract

Pathogenic E. coli are a significant threat both as a foodborne pathogen and a leading cause of urinary tract infections. Conventional methods to detect these microbes require centralized laboratory facilities and specialized equipment, as well as hours to days to complete. We have developed a sensitive electrochemical sensor to covalently capture, detect, and quantify viable pathogenic E. coli from complex matrices with a detection limit of 12 CFU/mL and a linear range of detection up to 107 CFU/mL. The technology enables quantification within two hours on disposable electrodes, even from milk and artificial urine. Endogenous E. coli were successfully detected from commonly-contaminated samples, including eggs, raw chicken, spinach, and romaine lettuce, in addition to an infected urine sample. The E. coli quantification tracked well with the current gold-standard of colony counting. This platform represents a major step in the development of field-deployable sensors to detect these dangerous microbes.