TABLE 3.

Comparison of polymer brush–coated AuNPs and amphiphilic block co-polymer–encapsulated AuNPs.

	Amphiphilic polymer brush attached to the AuNP surface	Amphiphilic block co-polymer encapsulation of AuNPs
Conjugation method	Covalent gold–thiol (Au–S) bond	Hydrophobic–hydrophobic interactions41,47
Advantages	Stable in organic solvent or water	Polymer thickness can be easily tuned
	Both hydrophilic and hydrophobic polymer brushes can be attached to the AuNP surface	The polymer layer can cover the whole AuNP
	Can be self-assembled into various nanostructures, such as dimers and vesicles	Only amphiphilic block co-polymers are needed to encapsulate AuNPs
	The ratio of hydrophilic to hydrophobic polymer brushes can be easily tuned
Limitations	The polymer graft density is limited because of the steric hindrance of the polymer brush	The AuNPs should be modified with hydrophobic ligand first before encapsulation by the polymer
	The reaction method needs longer time to grow hydrophobic polymer brushes	The AuNPs cannot disperse in solvents that can dissolve the hydrophobic polymer