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Abstract
A bacterial biosensor for the detection of benzene, based on the respiratory activity of Pseudomonas putida ML2 immobilized on gold screen‐printed electrodes, was developed. Benzene can be catabolized by the bacteria Pseudomonas putida ML2 and used as a sole carbon source. Its aerobic degradation has been conventionally measured using a dissolved oxygen probe, and the assay principle has now been transferred to the surface of a screen‐printed gold electrode configuration, enabling mass production, ease of use, and a more portable sensor system. The bacterial cells were immobilized using a novel technique incorporating the entrapment of the cells between the gold electrode surface and a cellulose acetate membrane attached to an adhesive ring around the working electrode. The screen‐printed sensor displayed comparable responses to measurements based on the oxygen probe, with a linear detection range between 0.01–0.1 mM benzene and similar response characteristics. However, the lifetime of the sensor was seen to be short and unstable when several measurements were carried out using the same electrode, indicating its potential application as a single‐use device. This paper presents the development of a bacterial biosensor for the detection of benzene, based on low‐cost and mass producible screen‐printed electrodes, coupled to a portable potentiostat.