Biosensors for environmental monitoring

A biosensor is an analytical device that combines a biological component with a physical detector for identifying or quantifying specific compounds within a sample. The biological selective element, for example an antibody or enzyme, usually has high binding affinity and selectivity for a particular analyte (the substance being analysed).

In the most common biosensors, a biological element that has been immobilised on a solid surface binds to a target analyte within a sample mixture. This interaction is measured by a special transducer, which converts the biochemical signal into a measurable electrical signal that is proportional to the analyte concentration.

The EU-funded ‘Biosensor nanoarrays for environmental monitoring’ (BIOMONAR) project developed a new generation of sophisticated biosensors for monitoring environmental pollutants and pathogens. These combine the advantages of existing sensor systems with an unrivalled flexibility for a multitude of different targets.

BIOMONAR developed three different sensor platforms consisting of a solid surface, a lipid vesicle or a living bacterial cell, each containing a common biological sensor.

For the biological component, researchers chose a bacterial protein called periplasmic binding protein, which interacts strongly with target molecules via a specific binding pocket. Since the binding pocket's specificity can be tailored to suit whichever target molecule scientists want to detect, BIOMONAR's biosensors have potentially unlimited sensing capability.

This strategy will support EU environmental policy by selectively and sensitively detecting a panel of target compounds. In particular, pollutants and pathogens can be identified in complex environmental mixtures.