Responsive multidomain free-standing films of gold nanoparticles assembled by DNA-directed layer-by-layer approach.

Responsive free-standing films of gold nanoparticles are fabricated by a new approach combining the programmable DNA-directed self-assembly and the layer-by-layer (LbL) thin film fabrication technique. This approach allows for the assembly of multidomain nanoparticle films with each domain possessing distinct properties in response to external stimuli, which is essential for the formation of dynamic nanostructures. Large area free-standing films of DNA-modified gold particles are fabricated by the selective melting of a sacrificial nanoparticle domain, taking advantage of the unique sharp melting transition of DNA-modified gold nanoparticles. Furthermore, we show that released multidomain films can be designed to further split into multiple intact daughter films in a precisely controlled manner, demonstrating that this new approach provides a powerful means to fabricate free-standing nanoparticle films that are capable of programmable transformation.