Biosensor for water toxicity monitoring

A biosensor for detecting water contaminants comprising

• a microbial fuel cell compartment, the microbial fuel cell compartment comprising (i) at least one opening to allow water into and out of the microbial fuel cell compartment, (ii) an anode comprising electroactive microorganisms, and (iii) a cathode, wherein:
• the anode is electrically and physically separated from the cathode,
• the anode is anaerobic or micro-aerobic and comprises electroactive microorganisms, and
• the cathode is aerobic;
• a storage compartment comprising a biodegradable carbon source, the storage compartment being in communication with the anode to supply the biodegradable carbon source to the electroactive microorganisms at a controlled rate to maintain the chemical oxygen demand (COD) at the anode between about 10 mg/L to about 50 mg/L;
• an electric impedance load electrically connected to the anode and the cathode thereby forming an electric circuit with the microbial fuel cell compartment;
• an electric switch within the electric circuit forming an intermittent electrical connection between the microbial fuel cell compartment and the electric impedance load;
• an electric sensor within the electric circuit to measure an electric parameter of the electric circuit;
• and
• a control system coupled to the electric switch and the electric sensor, the control system configured to receive a measurement from the electric sensor, and outputting an indication signaling the presence or absence of the water contaminants based on the measurement,
• wherein the control system is configured to intermittently activate the electric switch for a period of time, a measuring period, to allow measurement of the electric parameter, such that during operation of the biosensor the electric switch is off between measuring periods.