NORDICNANO

For this project we aim to explore a novel invention for the NanoSIMS that allow a better focus and higher current for the oxygen source to be used for positive ion imaging. We have access to this, hyperion source20, through a recent collaboration with Cameca, the manufacturer of the NanoSIMS, and wish to study whether the improved ion current will allow fast detection of NMs in sections with the precision required for these kind of analytical challenges and faster than in our current method, where analysis time is relatively long (4-5h per image) and therfore also costly. Higher ion current would mean a more cost-effective analsyis.
A new approach to the use of ToF-SIMS for mapping of NMs in sections of e.g. Daphnia and algae will be developed. ToF-SIMS is a faster imaging technique and is as sensitive as NanoSIMS but with a lower spatial resolving power. An advantage is that ToF-SIMS has the ability to map NMs and obtain molecular information simultaneously. Hence biological processes in response to NMs can be determined. Albeit ToF-SIMS lacks the lateral resolving power of the NanoSIMS one advantage of ToF-SIMS is the ability to map larger scale objects such as an entire Daphnia. This could lead to a better understanding of large-scale processes occurring in biological tissue and plants. A unique opportunity since we have both techniques avilable, is to explore the complementarity of both SIMS techniques by first analyzing samples with ToF-SIMS (which can be considered non-destructive) and then analyzing the same sample with the NanoSIMS. This can establish a method to obtain both larger scale molecular information with high magnification data from showing a precise localization of for instance UNPs.
Work remains on establishing more standards for quantitative imaging of isotopic ratios. We wish to develop further standards from Certified Reference Materials ( CRM U200, etc.) Consequently, a significant part of the work (30%) will consist of developing a library of standards. In house standards will be made with an epoxy or resin matrix containing known concentrations and isotopic compositions of radionuclides (with focus on Th for 2022).