Environmental Sensing of Aquatic Systems at the University of Geneva

Abstract

Aquatic environments are complex living systems where biological and chemical constituents change rapidly with time and space and may exhibit synergistic interactions. To understand these processes, the traditional approach based on a typically monthly collection of samples followed by laboratory analysis is not adequate. It must be replaced by high-resolution autonomous in situ detection approaches. In our group at the University of Geneva, we aim to develop and deploy chemical sensor probes to understand complex aquatic systems. Most research centers around electrochemical sensing approaches, which involves: stripping voltammetry at gel-coated microelectrode arrays for direct measurements of bioavailable essential or toxic trace metals; direct potentiometry for the measurement of nutrients and other species involved in the nitrogen and carbon cycles; online desalination for oceanic measurements; the development of robust measurement principles such as thin layer coulometry, and speciation analysis by tandem electrochemical detection with potentiometry and dynamic electrochemistry. These fundamental developments are combined with instrument design, both in-house and with external partners, and result in field deployments in partnership with environmental researchers in Switzerland and the European Union.

In-Line Acidification for Potentiometric Sensing of Nitrite in Natural Waters

“…The importance of the reliable long-term monitoring of nutrient species (nitrites, nitrates, phosphates) in natural water lies in their significant role as indicators of anthropogenic activities that perturb aquatic ecosystems. − Currently established approaches for nutrient detection involve sample extraction using power intensive pumps, followed by analysis by expensive centralized laboratory devices, while in situ chemical analyzers have largely been restricted to the measurements of conductivity, temperature, and dissolved oxygen. , The sampling procedures are likely to result in undesired alterations of the samples and the loss of useful information. For these reasons, the concept of decentralized sensors for the in situ monitoring of nutrients as well as other species has become very attractive for environmentalists …”