Au@mSiO₂ core-shell nanoparticles loaded with fluorescent dyes: synthesis and application for imaging performance

Here, Au@mSiO2 core-shell nanoparticles were easily synthesized by a one-pot method. Positively charged alkyl chains with different lengths were modified on the surface of the particles. Thus composite nanoparticles with different potentials and hydrophilic interface properties were prepared. Based on the charge properties of the shell surface, the process of loading dyes was simplified by the strong electrostatic adsorption between the particle surface and the heterogeneous negatively charged dyes. The fluorescence intensity and fluorescence lifetime of the loaded fluorescent dyes showed that the dyes could not produce effective tunneling in the mesoporous materials, which was limited to the surface of the particles, which is beneficial for the subsequent research on the loading or release of nanoparticles. After loading, the nanoparticles still exhibit a high fluorescence intensity, enabling dual-mode microscopic imaging (TEM and fluorescence).