The excessive use of pesticides compromises the environment and human health worldwide. Effective use of pesticides in industry and agriculture requires in situ and online monitoring of water quality. The aim of this project is to improve the knowledge in signal processing of MFC biosensors to promote practical applications.

Project outline

The project aims to develop a biosensor to detect pesticides in water with the following characteristics:

• Based on a photosynthetic sediment microbial fuel cell (p-SMFC).

• Autonomous.

• Self-powered.

• Cost-effective.

• Robust, suitable for long-term deployment.

• Capable of in situ and online monitoring of water quality.

Project objectives:

• To design a continuous and real-time MFC biosensor.

• To prove the ability of the sensor to detect components of interest.

• To develop a model to interpret and predict the sensor’s output.

• To validate the sensor in the field.

Science

The increasing amount of chemicals used in industry and agriculture are polluting the water bodies by runoff, diffusion and leaching processes. These pollutants are a threat both to human health and the environment. Consequently, the Water Framework Directive has identified 33 priority substances that have to be controlled and limited. Among these, there are several compounds used in agriculture as pesticides and herbicides. These substances are currently monitored using analytical methods, such as chromatography or mass spectroscopy. These methods are expensive, require sample collection and cannot provide a continuous, online measurement. Therefore, there is a need to develop an online, continuous and real time sensors for water quality monitoring. Biosensors based on biofuel cells are rising as a promising deployable and self-powered technology for online and in-situ monitoring. The project scope is to develop a biofuel cell-based sensor capable of detecting the components of interest, to assess its suitability for field monitoring and to improve the signal processing.

Impact

A self-powered p-SMFC has been developed and tested for detection of atrazine in water. The presence of algae enhances the durability of the biosensor. Key findings:

• The biosensor detects the legal EU limit concentration of 0.1 µg L-1 on Atrazine.

• The detection is instantaneous.

• Is resilient to multiple toxic events, yet the sensor loses sensitivity over time.

• The power output is enhanced by the presence of the toxicant.

This is the PhD project of Dolores Gonzalez, supervised by Dr Mirella Di Lorenzo. During her PhD, Dolores has set the proof of principle on the use of biofuel cell biosensors for detection of atrazine. This work was submitted to Frontiers: “Effect of electrode properties on the performance of a photosynthetic microbial fuel cell for atrazine detection”.

Dolores was also recipient of a scholarship for a Summer School in biofilm characterisation at SCELSE, Singapore. She is now working on the prototype for in-field applications of the self-powered biosensors for water quality monitoring. The preliminary results of this work was presented as a proceedings article in an international conference on Fuel Cells as: “Investigating the use of Photosynthetic Sediment Microbial Fuel Cells for pesticide detection in water”.