Developing Chemical Sensors for Environmental Citizen Science


Runoffs from industry, agriculture and urban settings pollute our water. This leads to major pressures on the health of humans and ecological systems. It is thus vital to monitor water quality regularly and with robust methods. However, traditional monitoring tends to rely on sending an expert in the field to take samples, which only gives sporadic information. As a result, we only a have a limited understanding of the dynamics of pollutants in the environment. It is thus challenging to achieve cost-effective and targeted environmental management.

We have an urgent need for gathering more data at low-cost. We need to go beyond occasional measurement in a small number of locations. What is needed is chemical sensing of pollutants at frequent timepoints and in many locations. This will enable better quantification of trends and pressures of pollutants in the environment. It will underpin predictive modelling. It will provide the foundation for robust and cost-effective management of the aquatic environment.


We want to achieve frequent sensing of our waters by developing simple-to-use and low-cost chemical sensor devices. Such sensors can then be operated by members of the public. This allows us to gather chemical data through Citizen Science. The readouts from our devices will be captured through a phone camera and uploaded through an app. From this data, we can build a picture of a larger area and more time points – impossible to achieve by sending expert scientists into the field in isolated locations at isolated time points.

We have previously developed paper-based analytical devices (PADs) for colour readout of nutrients in freshwater at ppm level. The user simply dips the PAD into a water sample. The liquid then wicks up inside and interacts with our pre-loaded substrates. These substrates change colour when they react with the analyte of interest. The user then takes a photograph and uploads it. Such paper devices are cheap to manufacture. They are also lightweight and can thus be distributed easily. Furthermore, they can be easily disposed.

Scope of PhD project

In this project, we want to access pharmaceuticals accumulating in the environment. We will  design and test an environmental sensor system for both pre-concentration and readout of pollutants in our water systems. It is now well established that many pharmaceuticals are present in the environment at ppb levels. We will focus on compounds that are frequently detected, including antibiotics and anti-inflammatories. Colour readout with substrates embedded in the paper devices works well in the ppm to high ppb range. To assess analytes at lower concentrations for on-site measurement, we will develop simple-to-use push filters that can interface with the PADs. We will trial filter materials with different surface functionalisation and porosities. We will also try different strategies to interface the filter with the captured pollutant to the readout PAD.

To ensure our devices and workflows are fit for citizen-led sampling, we will liaise with local volunteer groups through existing contacts, such as the Canal and Rivers Trust, and international partners in Africa and Southeast Asia. Studying on this project, you will  develop extensive skills in science communication with a range of cultural groups. Our obtained data will enable a deeper understanding of the source, transport, and persistence of environmental contaminants.

Requirements for Candidate

The key requisite for the PhD candidate is an enthusiasm to immerse yourself into a multidisciplinary research environment. We bring together environmental sciences with chemistry and science communication. The position will suit a student with a degree in chemistry, biochemistry, environmental sciences or a related discipline. The student will join an exciting research and training environment. They will be embedded with ongoing projects for sensor development, have access to our Lab-on-a-Chip Fabrication and High Performance Computing Facilities. Through our Environmental Scientists, we also have access to a wide range of sample sites including streams and rivers, aquaculture farms and estuarine/oceanic sites.