Purpose: Since an outbreak of foodborne pathogens may have a severe impact on society resulting in illness, fatalities and financial losses, a rapid, cost-effective, and early detection biosensor would be a valuable tool not only for the food industry but also for regulatory bodies. In this work, the aim is to fabricate a flexible, label-free electrochemical biosensor based on chemiresistive and voltammetric techniques for the detection of Escherichia coli (e.g., E. coli O157), responsible for numerous foodborne and water-borne infections worldwide.
Methods: The biosensor is constructed on electro-spun membrane by synthesizing chemically sensitive conductive functionalized polymeric thin film to immobilize the analyte detecting molecules. The functional conductive thin films are obtained by co-polymerization of 3, 4-ethylenedioxythiphene and 3-thiopheneethanol and are produced via oxidative chemical vapor deposition (oCVD). oCVD can be used to deposit films with thicknesses ranging from Angstroms to microns onto many kinds of substrates such as paper, fabric, plastic, and glass.
Results: Real time detection and monitoring of E. coli with a lower than 10 CFU/ml level has been measured by chemiresistive and voltammetric techniques in this biosensor configuration.
Significance: Besides its sensitivity, ease of use makes it deployable for in-field detection of food pathogens. The high surface area of the biosensor detector membrane allows processing of very large sample sizes, a character which many potential biosensor platforms lack.