The rising acidity in the oceans from CO2 in the atmosphere contributes to dissolved inorganic carbon (DIC) in the shallow surface waters. DIC can be considered as the dissolved carbon bound to oxygen in small molecules (i.e. dissolved CO2, bicarbonate and carbonate). DIC is in balance with both the atmospheric CO2 and what is termed 'Blue Carbon', which is carbon in the ocean bound up as carbon chains, plants and animals (i.e. organic carbon) in coastal and marine ecosystems. Important to this project, pH is one of the few critical parameters that can be measured continuously in rivers and oceans to observe DIC and help us control and monitor the impact and effect of our carbon emissions.

Our aim is to directly address the current lack of pH sensors available that can withstand the harsh conditions of rivers and oceans by making low cost graphene materials that are sufficiently 'robust' and 'sensitive' to become the mainstream environmental sensor networks of the future. The proposal takes a problem-driven, multidisciplinary approach to develop a cost-effective solution to monitoring DIC and the impacts of carbon released into rivers and coastal waters. Our interdisciplinary team intend to advance sensors for pH measurement via focused graphene sensor development aligned with this major societal challenge, with readiness to be interfaced with leading industry-led technology.

Technical Abstract:
Global carbon dioxide (CO2) fluxes and rising acidity in rivers and oceans are buffered by the dissolved inorganic carbon (DIC) equilibrium in surface waters. pH is therefore a critical parameter needed to monitor DIC and the measurement of pH and DIC will ultimately allow us to monitor and control aquatic carbon emissions that leak from land to the ocean or diffuse across the sea surface.

The proposal takes a problem-driven, collaborative, multidisciplinary approach to develop a cost-effective solution to monitor emissions and impacts of carbon released into riverine and coastal waters. To deliver this project we have assembled a team of experts spanning the fields of marine and environmental science, analytical chemistry, graphene sensors, electronics and nanotechnology.

Our aim is to directly address current field pH sensor limitations by synthesizing functionalized graphene materials that are suitably robust and sensitive to become the mainstream environmental sensors of the future. We will then trial sensors and evaluate current sensor networks and field platforms for graphene sensors in both catchment and marine settings in the UK. The University of Plymouth (UoP) and Plymouth Marine Laboratory (PML) teams will link industry project partners (ProMare, IBM, Silicon Austria), higher education and environmental intelligence experts. The integrated approach ensures 'systems thinking' towards the development of large-scale pH sensor networks for application in catchments and coastal regions.