XAS study of nanosized and aggregation effect in Au nanoparticles for biomedical applications

Metal nanoparticles (NPs), such as Au, are widely employed for biomedical applications in the fields of diagnosis or drug/gene among others. They exhibit a variety of properties, being the localized surface plasmon resonance (LSPR) one of the most recognized. The LSPR band depends on several properties of the NPs and surrounding media, which alter the physical properties and thus the final response in their specific application. The aim of this proposal is to study, by XANES and EXAFS techniques at the Au L3-edge, the electronic and structural modifications induced in different Au NPs by changing their size, shape and aggregation state to correlate with the plasmonic and photothermal response. 3D aggregates of different dimensions will be analyzed determining the structural variations and the disorder effects generated in the nanostructures by the biological media. Cluster formation of NPs depends on the size and shape of NPs and it is a key parameter in the biomedical applications.