Synthesis of multi-branched plasmonic gold nanostructures

• Grant number: 23/02558-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2023
• End date: December 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Valeria Spolon Marangoni
• Grantee: Shaian José Anghinoni
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

The interaction between metallic nanostructures and electromagnetic radiation results in interesting effects, which mainly occur due to the localized surface plasmon resonance (LSPR). This effect results in a coherent and collective oscillation of electrons on the metal surface with an increase in light absorption and scattering at specific wavelengths (resonant). By modifying the size and shape of the material, it is possible to shift the absorption wavelength to specific regions of the spectrum. For example, by changing the shape of gold nanoparticles from spheres to rods (nanorods), the absorption band shifts from the visible region to the near-infrared region. Interaction with electromagnetic radiation can also result in the excitation of electrons to higher energy levels (hot electrons) which can be transferred to molecules on the surface of the particles, resulting in catalysis of various types of reactions. Branched metallic nanostructures have regions of high reactivity called hot spots, where it is found a high concentration of hot electrons. In this scientific initiation project, we aim to develop a new nanomaterial that combines the optical properties of nanorods with the high reactivity of hot spots by developing multi-branched gold nanorods. Emphasis will be given to the synthesis of this system, focusing on the development of strategies for efficient growth of the branches on the surface of the nanorods. The nanotoxicity of these systems may also be evaluated and compared with equivalent systems without branching, allowing investigation of the specific effect of branching on interactions with biomolecules.