Gram-Scale Synthesis and Biofunctionalization of Silica-Coated Silver Nanoparticles for Fast Colorimetric DNA Detection

Abstract

A direct silica-coating method has been developed for the gram-scale synthesis of well-dispersed [email protected]₂ nanoparticles. Subsequent surface functionalization via the well-established silica surface chemistry provided arching points for straightforward bioconjugation with amino-terminated oligonucleotides. Fast hybridization kinetics of the resulting robust oligo-modified [email protected]₂ nanoprobes with complementary target oligonucleotides render themselves very useful for the fast colorimetric DNA detection based on the sequence-specific hybridization properties of DNA. Additionally, the reliable protocols developed in this study for preparing and functionalizing [email protected]₂ nanoparticles can be readily extended to other silica-coated nanoparticles, which can also provide a specific platform for the covalent attachment of biomolecules such as amino-rich proteins, enzymes, or amino-terminated oligonucleotides for diverse bioapplications.