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Postgraduate research project

Lateral-flow field tests for marine macronutrients

Type of degree
Doctor of Philosophy
Entry requirements
2:1 honours degree
(View full entry requirements)
Faculty graduate school
Faculty of Engineering and Physical Sciences
Closing date

About the project

In this project you will be developing lateral-flow-style tests for in-the-field quantification of macronutrients in seawater, making use of metal-organic-frameworks (MOFs) as the sensing element. MOFs are crystalline porous solids that can be rationally designed as receptors for specific molecules, and the project team has already developed protocols for preparing MOF-based materials for lateral flow devices.

Nutrient molecules, such as nitrate and phosphate, underpin the natural cycles of life within the oceans and seas. They are essential for healthy phytoplankton growth and hence constitute the ultimate base of the marine food chain. They can also be potentially harmful. Nutrient pollution is a real problem in coastal waters, with human input from agricultural run-off and sewage often leading to toxic algal blooms. Measuring the concentration of marine nutrients is essential for both understanding how our oceans work and safeguarding against harmful pollution.

Traditionally, nutrient levels are measured by taking samples and transporting them to a lab for analysis. Transport costs fundamentally limit the number and frequency of measurements and ultimately how well we can monitor nutrient levels. This project looks to a different approach by developing lateral-flow diagnostics like those used for home pregnancy- or COVID-testing. As no sample transport is required, they offer a much cheaper alternative, allowing widespread frequent testing with significant potential impact in low resource parts of the world.

In practice you will be required to synthesise MOFs from literature procedures, integrate them in paper devices, and then design and 3D-print device housings. You will work through the major macronutrients (nitrate, phosphate, and ammonium first, then nitrite and silicate if time allows), in each case identifying appropriate MOFs, trialling them and comparing to standard colorimetric reagents. 

You will look at:

  • how easily they can be incorporated into a lateral flow device
  • analytical performance (accuracy, precision, sensitivity etc)
  • shelf life and stability
  • resilience against potential interferents (changing salinity, turbidity etc)

The final device should be low cost and user-friendly, so they can be used widely by non-experts. They should be capable of accurately measuring major macronutrients at typical environmental concentrations from a small (<1 ml) sample of water. They will be user-friendly, tested by yourself as well as oceanographers at sea.

 

Lead Supervisor

Dr Adrian Nightingale (University of Southampton)

Supervisors

Dr Darren Bradshaw (University of Southampton)

Dr Allison Schaap (National Oceanography Centre)

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