Fabrication of pH-Responsive Nanocomposites of Gold Nanoparticles/Poly(4-vinylpyridine)

Abstract

Novel nanocomposites of gold nanoparticle and poly(4-vinylpyridine) (Au@PVP) were fabricated through surface-initiated atom-transfer radical polymerization (SI-ATRP) at ambient conditions. The citrate-stabilized gold nanoparticles were first modified by a disulfide initiator for ATRP initiation, and the following polymerization of 4-vinylpyridine (4VP) occurred on the surface of gold particles. The assembled Au@PVP nanocomposites are pH-responsive because of the pyridyl groups, which are facially protonated and positively charged. At low pH ( 3.2), the polymer chains shrink and wrap around the gold particle surface, which results in the aggregation of gold nanoparticles with a thin shrunken polymer layer under TEM observation. Such assembled A...