Rapid electrochemical detection of using nickel oxidation reaction on a rotating disk electrode.

A standalone electrochemical method for detecting the bacterium in water was developed using a nickel electrode and no biorecognition element. Electric current responses from different concentrations were recorded based on their interaction with a locally formed electrocatalyst. A rotating disk electrode was used to minimize the mass transport limitations at the interface. Results from experiments with the rotating disk electrode also paved the way for hypothesizing the detection mechanism. The operating conditions were established for sensing the electric current responses in the presence of . The least-squares linear regression model was fit to the data obtained from currents of some known concentrations. This probe had a detection limit in the order of 10 CFU/ml. The response time to detect the presence/absence of was less than half a second, while the total assay time, including quantification of its concentration, was 10 min. The electric current response from a solution mixed with and showed current similar to only solution indicating the specificity of the sensor to respond to signals from . This electrochemical microbial sensor's uniqueness lies in its ability to rapidly detect by forming the catalyst locally on demand without the attachment of biorecognition elements.