• Farinha, José Paulo S.
• Sousa, Ana R.
• Pereira, André M.
• Martinho, Jose
• Rodrigues Pereira, Clara
• Rocha, Mariana
• Casteleiro, Bárbara

Abstract

<jats:p>Gold nanoclusters (AuNCs) with fluorescence in the Near Infrared (NIR) by both one- and two-photon electronic excitation were incorporated in mesoporous silica nanoparticles (MSNs) using a novel one-pot synthesis procedure where the condensation polymerization of alkoxysilane monomers in the presence of the AuNCs and a surfactant produced hybrid MSNs of 49 nm diameter. This method was further developed to prepare 30 nm diameter nanocomposite particles with simultaneous NIR fluorescence and superparamagnetic properties, with a core composed of superparamagnetic manganese (II) ferrite nanoparticles (MnFe2O4) coated with a thin silica layer, and a shell of mesoporous silica decorated with AuNCs. The nanocomposite particles feature NIR-photoluminescence with 0.6% quantum yield and large Stokes shift (290 nm), and superparamagnetic response at 300 K, with a saturation magnetization of 13.4 emu g−1. The conjugation of NIR photoluminescence and superparamagnetic properties in the biocompatible nanocomposite has high potential for application in multimodal bioimaging.</jats:p>

Topics

• nanoparticle
• nanocomposite
• photoluminescence
• gold
• Manganese
• magnetization
• saturation magnetization
• surfactant
• condensation polymerization