Details of Award
NERC Reference : NE/J017779/1
Nanosensors for pH determination in individual droplets and aerosol particles
Training Grant Award
- Lead Supervisor:
- Professor J Lead, University of Birmingham, Sch of Geography, Earth & Env Sciences
- Grant held at:
- University of Birmingham, Sch of Geography, Earth & Env Sciences
- Science Area:
- Atmospheric
- Earth
- Freshwater
- Overall Classification:
- Atmospheric
- ENRIs:
- Environmental Risks and Hazards
- Global Change
- Pollution and Waste
- Science Topics:
- None
- Abstract:
- pH is a fundamental parameter controlling the chemical and physical properties of an environmental system. For example, pH in individual aerosols and droplets determines the dissolution kinetics of metals and phosphorus. This has direct implications for global biogeochemical cycles because acidic pH promotes nutrient dissolution in dust, leading to increased supply of important nutrients to the global ocean and thus affects the Earth's climate system. pH in aqueous solutions also determines the phase partitioning of acids and bases in the atmosphere, for example the release of halogen species and oxidation of sulphur. Furthermore, pH is an important factor affecting the formation of secondary organic aerosols, and for this reason currently US NSF has allocated multi-million US dollars to investigate this issue. Limited indirect measurements and thermodynamic modelling provided useful information on the aerosol acidity but the derived pH is an average of a number of particles and is largely uncertain. Direct measurements of bulk cloud water pH have also been done before. However, the pH of individual droplets and aerosol particles has never been measured due to technical challenges, although it is well known that individual particles and droplets are extremely heterogeneous. The problem is an averaged pH value cannot represent the wide pH spectrum and therefore can lead to significant errors in climate models. For example, the simulated deposition fluxes of soluble Fe to the ocean is substantially lower assuming an averaged pH in dust aerosols. Since pH is a critical parameter in the study of tissue metabolism, neurophysiology, cancer diagnostics, muscle contraction, the development of in vivo pH sensors has been an active research for more than 20 years. Fluorescent sensors were advantageous over other techniques with respect to spatial and temporal resolutions and sensitivities. Sensors of more recent interest are the nanoparticle (NPs)-based probes, which can serves as reliable fluorescent reporters. In comparison to fluorescent dyes, nanoparticle-based probes are more useful as their fluorescence and chemistry can be modified more easily and optimised to maximise interactions with target samples and tailor fluorescence signals. This presents a great advantage in their environmental applications. The purpose of this project is to develop nanosensors for pH determination of individual droplets and particles, in a step wise approach given the complexity of the problem at hand. The first step of the research will be to develop pH nanosensors for application in algae, which is novel but requires less development considering the existing knowledge in biomedical sciences. In addition, both algae and NPs are routinely used in our laboratories and we have a good deal of expertise with both. The second step will be to develop pH nanosensors and to physically or chemically constrain the nanosensors on a two dimensional surface. This will then be used to collect laboratory generated individual droplets for further pH quantification. The third step will be to optimize the technique to apply it to individual particles generated from laboratory, e.g., fresh and aged sea salt particles. These steps represent different levels of complexity and the first two steps will serve as the stepping stones for a successful development of nanosensors for pH measurements of individual particles with tiny amounts of water compared to droplets or living cells. The PhD student will be given extensive training in generic skills via programs in the GEES from supervisors with a long background in this area. Specific analytical skills will be provided in the research group with many academic and research staff with field, laboratory and modelling expertise. The student will also gain a considerable training experience from contact with many other bodies, summer schools, and/or overseas collaborative research.
- NERC Reference:
- NE/J017779/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Analytical Sci and Tech
This training grant award has a total value of £70,596
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|
| £13,812 | £8,500 | £48,285 |
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