Continuous measurement of acute toxicity in water using a solid state microrespirometer

This work presents the first true solid-state microrespirometer. It consists on a naturally developed biofilm of Pseudomonas aeruginosa over a Nafion modified array of gold microdisc electrodes. Such a device can be used to monitor acute toxicity in water streams based on the oxygen reduction current recorded at the microelectrode array. When a healthy biofilm is exposed to a toxic stream the bacteria conforming stop breathing which results in an immediate increase of the oxygen supply reaching the microelectrode array. brication and use of such a microrespirometer is described, and a possible operation mode for a real application is presented. Given that different waters may contain toxic compounds of diverse nature, the respirometer presented here provides qualitative information only.