Development of an original biosensing platform enabling the non-invasive real-time monitoring of oxidative stress in aquatic microorganisms in contact with engineered nanoparticles.
Background
The potential release in the environment of engineered nanoparticles (ENPs) and their subsequent ecotoxicological impact is becoming a main concern that needs to be addressed. Among different detrimental effects caused by ENPs, oxidative stress is reported as one of the major toxicity mechanisms; however, available data are limited and rather controversial, in particular for aquatic microorganisms. Thus, a deeper understanding of the interaction of ENPs with microorganisms is needed, as well as new methods adapted for its evaluation.
Aim
The objective of this multidisciplinary project is to develop an original plasmonic-based biosensing platform enabling multiplexed monitoring of a series of oxidative stress (bio)-markers, excreted by aquatic unicellular microorganisms such as algae and bacteria exposed to ENPs. The foreseen sensing approach is based on the absorption peak of cytochrome c’s heme group, which directly depends on its redox state (FeIII/FeII). The redox state of the heme group is also strongly coupled to the oxidation potential of its aqueous environment and thus affected by the presence in the cell suspension of reactive oxygen species (ROS), namely hydrogen peroxide H2O2, superoxide O2-, or nitric oxide NO. The presence of toxicants such as ENPs will trigger defence mechanisms; activate the production of scavenging enzymes and reducing agents that will diffuse from intra- to extracellular media. Hence, extracellular concentration monitoring of these ROS markers constitutes a non-invasive monitoring of cell suspensions. The proposed detection mechanism relies on the significant enhancement of the dark-field absorption cross-section of the cytochrome c immobilised on plasmonic nanoantenna structures.
Significance
The sensing platform developed in this project will enable the non-invasive measurement of oxidative stress in aquatic microorganisms in contact with ENPs. This will further our understanding of the corresponding ecotoxical processes.
Original title: Non-invasive continuous monitoring of the interaction between nanoparticles and aquatic microorganisms
Grant: CHF 443'710.-
Duration: 36 months
Project leader
- Prof. Olivier Martin