[Fully-funded ARIES studentship for 3.5 years, including tuition fees, maintenance stipend of £20,780 per annum (2025/26 rate; 2026/27 rate TBC), and research costs.] This fully-funded PhD studentship at the University of Plymouth offers an exciting opportunity to develop next-generation sensors for tracking calcium and magnesium in marine ecosystems. The project addresses critical gaps in our understanding of how Ca²⁺ and Mg²⁺ concentrations fluctuate in coastal waters, which is essential for predicting the impacts of ocean warming and acidification on marine calcifying organisms. Recent global surveys have revealed significant variability in these ions due to factors such as river runoff, coastal upwelling, and biological activity, but existing data are limited to isolated measurements. The successful candidate will join the Sensor Technologies Research Group (STRG) to design, fabricate, and validate innovative screen-printed ion-specific electrodes for continuous, real-time monitoring of Ca²⁺ and Mg²⁺ in coastal seawater. Laboratory validation will be followed by field testing in Plymouth Sound, capturing ionic fluctuations over multiple tidal cycles. Comprehensive training will be provided in screen-printing techniques for conductive materials, chemical functionalization for sensor conversion, and electrochemical data analysis. Additional instruction will cover electrode characterization using scanning electron microscopy and spectroscopic techniques, as well as specialized training in Mg/Ca data interpretation and environmental applications. The ideal applicant will have strong laboratory and analytical skills, a passion for applying chemical knowledge to environmental challenges, and preferably some programming experience. Eligibility requires a first or upper second class honours degree in Earth, Environmental, Biological Science, Chemistry, or a relevant Masters qualification. Non-native English speakers must meet the university's language requirements (IELTS Academic 6.5 overall, minimum 5.5 in each component). The studentship is funded for 3.5 years, including tuition fees, a maintenance stipend of £20,780 per annum (2025/26 rate; 2026/27 rate TBC), and research costs. The project will start on 1 October 2026. Applications must be submitted by 7 January 2026. Shortlisted candidates will be invited for interview after the deadline. For informal inquiries, contact Dr Uwe Balthasar at [email protected]. For application details and supporting document requirements, visit the University of Plymouth's research studentship webpage.