Synthesis, Functionalization, and Bioconjugation of Monodisperse, Silica-Coated Gold Nanoparticles: Robust Bioprobes


  • This work was supported by the Institute of Materials Research and Engineering and the National University of Singapore. Supporting Information is available from Wiley InterScience or the author.


Herein, we report an efficient process for preparing monodisperse Au@SiO2 nanoparticles using homogeneous shaking and without the use of surface-coupling silane agents or large stabilizers. The resulting pure-silica surface of the Au@SiO2 nanoparticles is very important for straightforward surface functionalization with different functional groups via well-established silica surface chemistry. Subsequent covalent bioconjugation of the aldehyde-functionalized Au@SiO2 nanoparticles with various biomolecules is successfully employed to make robust nanoprobes for fast, colorimetric DNA and protein detection based on the sequence-specific hybridization properties of DNA and the specific binding affinity between proteins, respectively.