Radiation-induced preparation of core/shell gold/albumin nanoparticles

ESTEFANÍA ACHILLI; CONSTANZA FLORES; MARIANO GRASSELLI

Peninsula of Giens

Simposio; 12th Ionizing Radiation and Polimers Symposium (IRAP); 2016

International Atomic Energy Agency

Nanoparticles (NPs) are one of themost promising nanomaterials to be used in the biomedical field. Gold NPs (Au-NPs)have been covered with monolayers of many different molecules and macromoleculesto prepare different kinds of biosensors. However, these coatings based onphysisorption methods are not stable enough to prepare functional nanomaterialsto be used in complex mixtures or in vivo applications.The aim of this work was to prepare aprotein coating of Au-NPs based on a protein multilayer covering, stabilized bya novel radiation-induced crosslinking process. Albumins from human and bovinesource were added to Au-NPs suspension and followed by ethanol addition toinduce protein aggregation. Samples were irradiated with a gamma source at 10kGy to induce a protein crosslinking according to recent findings. Samplescontaining 30 %v/v ethanol showed a plasmon peak at about 532 nm, demonstratingthe presence of non-aggregated Au-NPs. Using higher ethanol concentrations, theabsorbance of plasmon peak showed NP aggregation. By dynamic light scattering measurements,a new particle population with an average diameter of about 60 nm was found.Moreover, TEM images showed that the NPs had spherical shape and the presenceof a low-density halo around the metal core confirmed the presence of theprotein shell. An irradiation dose of one kGy was enough to show changes in theplasmon peak characteristics. The increase in the chemical stability of proteinshell was demonstrated by the reduction in the NP dissolution kinetics in presenceof cyanate.