The aim of this research is to understand the structural confirmation of dextran coated iron oxide (Fe3O4) nanoparticles in the presence of Bovine serum albumin (BSA) in aqueous solution; the effects of the dextran coating shall be investigated over a range of pH values and BSA concentrations. The experiment seeks to explore the nature of the interactions between BSA and the coated NPs, and to verify whether, the BSA forms a secondary shell or competes with the dextran for the NP surface. Preliminary SANS (Figure 1) and light scattering measurements indicate that the structure of the aggregates is unchanged upon addition of BSA, however, the size of the aggregates increased. This project is supported by the Welsh Government Sêr Cymru programme and the National Research Network (Wales).