Importance of the Structural and Physicochemical Properties of Silica Nanoshells in the Photothermal Effect of Silica-Coated Au Nanoparticles Suspensions.
Penelas, M. J., Arenas, G. F., Trabadelo, F., Soler-Illia, Gjaa, Moya, S. E., Angelome, P. C. and Hoppe, C. E.
Division Polimeros Nanoestructurados, Instituto de Investigaciones en Ciencia y Tecnologia de Materiales (INTEMA), UNMdP-CONICET y Departamento de Quimica, UNMdP, Av. Cristobal Colon 10850, B7606BWV Mar del Plata, Buenos Aires, Argentina.
Instituto de Nanosistemas, Universidad Nacional de San Martin, Av. 25 de Mayo 1021, San Martin, B1650 Buenos Aires, Argentina.
Laboratorio LASER, ICYTE, UNMdP-CONICET, Av. J. B. Justo 4302, B7608FDQ Mar del Plata, Buenos Aires, Argentina.
Laboratorio de Electronica, Instituto de Investigaciones en Ciencia y Tecnologia de Materiales (INTEMA), UNMdP-CONICET,Av. Cristobal Colon 10850, B7606BWV, Mar del Plata, Buenos Aires, Argentina.
CIC biomaGUNE, Paseo de Miramon 182, 20014 Donostia-San Sebastian, Spain.
Gerencia Quimica & INN, CAC, CNEA-CONICET, Av. General Paz 1499, 1650, San Martin, Buenos Aires, Argentina.
In this work, monodisperse silica-coated gold nanoparticles (NPs) were synthesized and used for obtaining aqueous colloidal dispersions with an optimum relationship between colloidal stability and photothermal activity. The idea behind this design was to produce systems with the advantages of the presence of a silica shell (biocompatibility, potential for surface modification, and protecting effect) with a minimal loss of optical and thermal properties. With this aim, the photothermal properties of NPs with silica shells of different thicknesses were analyzed under conditions of high radiation extinction. By using amorphous, gel-like silica coatings, thicknesses higher than 40 nm could be obtained without an important loss of the light absorption capacity of the colloids and with a significant photothermal response even at low NP concentrations. The effects produced by changes in the solvent and in the NP concentration were also analyzed. The results show that the characteristics of the shell control both, the photothermal effect and the optical properties of the colloidal dispersions. As the presence of a silica shell strongly enhances the possibilities of adding cargo molecules or probes, these colloids can be considered of high interest for biomedical therapies, sensing applications, remote actuation, and other technological applications.
Langmuir 38(12): 3876-3886 (2022)