Development of electrochemical inhibition biosensor based on bacteria for detection of environmental pollutants

•This work is a part of ongoing research targeting the development of novel, simple, and cost effective methods for monitoring environmental pollutants.•In this work, we used simple electrochemical measurements for establishing the correlation between conductivity of liquid bacteria samples and immobilized bacteria.•The main focus of this work is on electrical characterisation of both free bacteria in solution and bacteria immobilized on the surface of metal electrodes.•This work proved the concept of a novel, simple and cost effective electrochemical bacteria-based sensor and sensor array for preliminary assessment of the presents of pollutants in water.

The main aim of this work is to develop a simple inhibition electrochemical sensor array for detection of heavy metals using bacteria. A series of electrical measurements (cyclic voltammograms) were carried out on samples of two types of bacteria, namely Escherichia coli and Shewanella oneidensis along with optical measurements (fluorescence microscopy, optical density, and flow cytometry) for comparison purposes. As a first step, a correlation between DC electrical conductivity and bacteria concentration in solution was established. The study of the effect of heavy metal ions (Hg2 +) on DC electrical characteristics of bacteria revealed a possibility of pattern recognition of inhibition agents. Electrical properties of bacteria in solution were compared to those for immobilized bacteria.