Controllable oligomerization: defying step-growth kinetics in the polymerization of gold nanoparticles

Random aggregation of nanoparticles typically leads to step-growth kinetics and thus a low concentration of dimers. Here, we report a one-step method to produce gold nanoparticle dimers by exploiting a polystyrene-block-poly (acrylic acid) shell. Methods to fine-tune the surface charge repulsion and swelling allow us to control the extent of aggregation, stopping selectively at dimers.