Detection of low levels of Escherichia coli by electrochemical impedance spectroscopy and singular value decomposition

•Label-free immunosensor for trace-level detection of E-coli.•Electrochemical impedance spectroscopy, EIS, in combination with single value decomposition, SVD for electroanalytical purposes.•Multivariate regression.

The first steps are reported in the development of a new ultrasensitive electrochemical biosensor for detection of Escherichia coli (E. coli) in water. Two gold electrodes in a sandwich flow-cell were modified with E. coli polyclonal antibody and exposed to three different concentrations of E. coli. Electrochemical Impedance Spectroscopy was used in combination with Singular Value Decompostion of the complex numbers to monitor the interactions at the electrode surfaces. A linear regression line in the concentration range 10-1000 CFU*ml-1 was obtained without use of redox probes or metal nanoparticles for signal amplification.