Finance

Physics

Nanotechnology

Organic chemistry

Dispersion stability

Physisorption

Colloidal gold

Optics

Engineering

Catalysis

Nanoparticle

Economics

Dispersion (optics)

Chemistry

Materials science

Ethylene glycol

Chemisorption

Chemical engineering

Polymer

PEG ratio

Nature Communications

Nano-sized metal particles are attracting much interest in industrial and biomedical applications due to the recent progress and development of nanotechnology, and the surface-modifications by appropriate polymers are key techniques to stably express their characteristics. Herein, we applied cyclic poly(ethylene glycol) ( c -PEG), having no chemical inhomogeneity, to provide a polymer topology-dependent stabilization for the surface-modification of gold nanoparticles (AuNPs) through physisorption. By simply mixing c -PEG, but not linear counterparts, enables AuNPs to maintain dispersibility through freezing, lyophilization, or heating. Surprisingly, c -PEG endowed AuNPs with even better dispersion stability than thiolated PEG (HS–PEG–OMe). The stronger affinity of c -PEG was confirmed by DLS, ζ-potential, and FT-IR. Furthermore, the c -PEG system exhibited prolonged blood circulation and enhanced tumor accumulation in mice. Our data suggests that c -PEG induces physisorption on AuNPs, supplying sufficient stability toward bio-medical applications, and would be an alternative approach to the gold–sulfur chemisorption.

Enhanced dispersion stability of gold nanoparticles by the physisorption of cyclic poly(ethylene glycol)