Detection and quantification of a wide range of hazardous substances (e.g. heavy metals) is required to minimise harm to the ecosystem of contaminated environments. Analytes of these hazardous substances can enter and accumulate in the food chain causing potential harm to humans. Current detection methods of contaminants in water and soil environments are not always practical as they are time-consuming, costly and require off-site testing. These limitations can be overcome using whole cell biosensors. The ability to genetically manipulate regulatory elements to produce a detectable and measurable signal with a range of sensitivities and specificities has resulted in the utilisation of commonly used laboratory microorganisms as biosensors. For whole cell biosensors to be feasible for the detection of contaminants in the environment, a wider range of microorganisms with integrated output systems is required. This study is focused on utilising electroactive bacteria (Pseudomonas, Shewanella and Geobacter) as biosensors. These microorganisms can interact directly with electrode surfaces and have the potential to be integrated into electronic devices. Redox-active proteins which are produced by these bacteria have specific electrochemical signals that can be detected using cyclic voltammetry. As a proof of principle in the development of integrated biosensors, genes encoding electroactive cytochromes have been cloned downstream of promoters and their cognate transcriptional regulators. These biosensors are being designed to generate electrochemical outputs in response to various analytes. The integration of Pseudomonas, Shewanella and Geobacter into electronic devices will potentially lead to the construction of a self-powering electrically integrated biosensor for detection of hazardous substances in the environment. The use of microbial biosensors overcomes the limitations of existing methods which require off-site testing and expensive infrastructure. This study highlights the potential applications of synthetic biology in detecting and quantifying environmental contaminants.