Hacking Photosynthesis: Biosensors for Herbicides and Beyond

The introduction of agrochemicals has drastically improved crop yields, largely thanks to the use of herbicides that kill crop competing weeds. Unfortunately, herbicides residues often find their way into our ecosystems, drinking water and food.

Current means to monitor herbicide residues utilize expensive, time-consuming methodologies such as liquid chromatography coupled to mass spectroscopy, a technique typically restricted to First world countries and trained users.

A biosensor provides a means for rapid, low-cost, sensitive herbicide detection that is widely accessible even in developing countries.

I have previously evaluated a biosensing platform using an electrode coated with bacterial reaction centres, but found that it was not sensitive enough to meet EU drinking water standards, was limited to sensing a small class of herbicide residues and was not stable enough under storage for widespread distribution.

To tackle the issue of low stability, I implemented a redox polymer transduction matrix, resulting in biosensor stability for hours during operation and months in storage.

I then approached the most challenging aspect of boosting biosensor sensitivity by re-designing the biological recognition element itself, using docking simulations to guide enzyme design that resulted in validated improvements in biosensor sensitivity in the lab.

This forms the platform for my research within the MSCA Postdoctoral fellowship, wherein I seek to push enzyme-herbicide binding affinities to reach a biosensor sensitivity that meets EU standards, expand the scope of sensing beyond a small class of residues, and sense not just single but multiple herbicide residues on a single test strip.

The results of this work will lead to a herbicide biosensor that approaches market viability, and lays the groundwork for a modular biosensing platform that can be extended beyond herbicides, to include biomarkers for monitoring health and detecting disease.