A novel, online probe to detect the concentration of Escherichia coli (E.coli) in water has been developed. Chronoamperometry was used to record the electrochemical current response from different E.coli concentrations based on their interaction with a locally formed catalyst on electrode surface, which occurs when a fixed potential is applied. A number of current responses that are specific to some known E.coli concentrations were recorded and used to develop a linear least squares regression model. The probe founded on this model had a detection limit of 10⁴ CFU/ml and percent error consistently less than 15% on log scale with a detection time of 10 minutes. The major advantage of this sensor lies in its rapid detection and on-site integration, minimizing the need for continuous physical monitoring.

Keywords:

Electrochemical sensor; Escherichia coli detection; Online probe