Clickable gold nanoparticles as the building block of nanobioprobes

A new method of fabricating "clickable" gold nanoparticles that could be used as the building block of nanobioprobes was described. On the basis of a well-developed strategy of encapsulating hydrophobic nanoparticles with a layer of amphiphilic polymers, cheap, easily prepared graft polymer was used as a modifier to prepare monodisperse azide-functionalized gold nanoparticles (AuNPs), which showed good stability in physiological solution. By conjugation with alkyne functional horseradish peroxidase (HRP) via click chemistry under mild conditions, the azide-AuNPs have demonstrated their potential in the fabrication of stable, bioactive nanobioprobes. Some critical problems in the fabrication of nanobioprobes, such as how to detect the number of bound biomolecules on nanoparticles and evaluate the bioactivities of nanobioprobes, are discussed in detail.