Silica Coated Bi2Se3 Topological Insulator Nanoparticles: An Alternative Route to Retain Their Optical Properties and Make Them Biocompatible

Blaž Belec; Nina Kostevšek; Giulia Della Pelle; Sebastjan Nemec; Slavko Kralj; Martina Bergant Marušič; Sandra Gardonio; Mattia Fanetti; Matjaž Valant

doi:10.3390/nano13050809

Silica Coated Bi₂Se₃ Topological Insulator Nanoparticles: An Alternative Route to Retain Their Optical Properties and Make Them Biocompatible

Nanomaterials (Basel). 2023 Feb 22;13(5):809. doi: 10.3390/nano13050809.

Authors

Blaž Belec¹, Nina Kostevšek², Giulia Della Pelle^{2

3}, Sebastjan Nemec^{4

5}, Slavko Kralj^{4

5}, Martina Bergant Marušič⁶, Sandra Gardonio¹, Mattia Fanetti¹, Matjaž Valant¹

Affiliations

¹ Materials Research Laboratory, University of Nova Gorica, 5000 Nova Gorica, Slovenia.
² Department for Nanostructured Materials, Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
³ Jožef Stefan International Postgraduate School, 1000 Ljubljana, Slovenia.
⁴ Department for Material Synthesis, Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
⁵ Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia.
⁶ Laboratory for Environmental and Life Sciences, University of Nova Gorica, 5000 Nova Gorica, Slovenia.

Abstract

Localized surface plasmon resonance (LSPR) is the cause of the photo-thermal effect observed in topological insulator (TI) bismuth selenide (Bi₂Se₃) nanoparticles. These plasmonic properties, which are thought to be caused by its particular topological surface state (TSS), make the material interesting for application in the field of medical diagnosis and therapy. However, to be applied, the nanoparticles have to be coated with a protective surface layer, which prevents agglomeration and dissolution in the physiological medium. In this work, we investigated the possibility of using silica as a biocompatible coating for Bi₂Se₃ nanoparticles, instead of the commonly used ethylene-glycol, which, as is presented in this work, is not biocompatible and alters/masks the optical properties of TI. We successfully prepared Bi₂Se₃ nanoparticles coated with different silica layer thicknesses. Such nanoparticles, except those with a thick, ≈200 nm silica layer, retained their optical properties. Compared to ethylene-glycol coated nanoparticles, these silica coated nanoparticles displayed an improved photo-thermal conversion, which increased with the increasing thickness of the silica layer. To reach the desired temperatures, a 10-100 times lower concentration of photo-thermal nanoparticles was needed. In vitro experiments on erythrocytes and HeLa cells showed that, unlike ethylene glycol coated nanoparticles, silica coated nanoparticles are biocompatible.

Keywords: biocompatibility; bismuth selenide; nanoparticles; photo-thermal material; topological insulator.

Grants and funding

The work was financially supported by the Slovenian Research Agency, research core funding No. P2-0412 and P2-0089, postdoctoral project No. Z2-2644, ARRS project No. J23034, J2-3040, J2-3046, J3-3079, J7-4420 and bilateral ARRS project No. BI-FR/23-24-PROTEUS-005.