A project undertaken at Monash University, and supervised by A/Prof Simon Corrie.
2,4-dichlorophenoxyacetic acid (“2,4-D”) is one of the most frequently used herbicides worldwide to control weeds in agricultural crops, forests and gardens. It was first registered in Australia ~50 years ago, and there are now >200 registered products available. Despite the benefits in terms of crop yield, there is concern over contamination of sensitive crops (e.g. cotton, grape vines) via spray drift of droplets, or leaching and runoff into waterways. As an example of the significant economic impact, ABC News recently reported that 2,4-D spray drift in Australia resulted in loss of ~30,000 hectares of cotton (an extremely water-intensive crop) costing up to $100M in lost product in the 2022/23 summer alone (Bradfield 2023). While significant efforts are being made to develop remediation methods to remove 2,4-D from the environment (Ramalingam et al, 2017), there are still no rapid monitoring tools to detect herbicide levels in affected areas immediately, without the significant delays associated with lab testing.
Our team aims to solve this problem by inventing a new platform technology for pesticide monitoring at the “point-of-need” with simple paper-based tests. In this Project specifically, we will engineer stable and highly active enzymes that react selectively with 2,4-D, yielding reaction products that can be detected by a simple colour change. These enzymes and the colour indicators will then be packaged into paper-based rapid tests (similar to COVID rapid antigen tests) for quick and easy detection of 2,4-D in agricultural samples.