Synthesis of thermosensitive hybrid structure gold nanotriangles coated with poly(N-isopropylacrylamide) for reversible confinement of molecules

In this work, we investigate a synthesis method for novel systems that involve the use of gold nanotriangles arrays (AuNTs) coated with poly(N-isopropylacrylamide) (pNIPAM) brushes, designed as smart platforms for the reversible confinement of bio-particles. Initially, we employed cost-effective nanosphere lithography to fabricate gold nanotriangles arrays. Next, polymer initiator groups were attached to the AuNTs surface through a spontaneous reduction approach, enabling exclusive functionalization of pNIPAM on the gold surface. Finally, we utilized surface-initiated atom transfer radical polymerization to graft pNIPAM brushes onto the gold surface. We systematically investigated the polymer initiator groups' grafting time and the polymerization time to control the thickness of the grafted pNIPAM brushes. Subsequently, we characterized the thermoresponsive properties of these hybrid structures using Atomic Force Microscopy (AFM) measurements, evaluating their ability to undergo on/off adsorption and desorption of polystyrene (PS) beads on their surface. Indeed, the combination of the thermosensitive pNIPAM polymer with AuNTs arrays results in the development of a precisely regulated two-dimensional active device which exhibits tunable properties with external temperature changes, making it a versatile platform suitable for a wide range of applications.