Multiamino polymeric capping of fluorescent silver nanodots as an effective protective, amphiphilic and pH/thermo-responsive coating

Abstract

Herein the in situ photochemical synthesis of silver nanodots (AgNDs) coated with new smart multi-amino polymers is reported. This fast, clean and highly efficient process provides new amphiphilic highly photoluminescent nanohybrids and smart properties (thermal, pH and light response). Furthermore, the polymeric coating over the silver nanoclusters avoids the strong tendency of silver nanodots to aggregate, gives protection against quenchers, tunes fluorescence emission and facilitates handling, storage and maintenance of the hybrids for long periods of time without loss of their photophysical properties. Therefore, a new family of multi-amino copolymers based on 2-amino-ethyl methacrylate protected with the t-butoxycarbonyl (Boc) group (Boc-AEMA) with a majority thermoresponsive monomer, 2-(2-methoxyethoxy)ethyl methacrylate (MEO₂MA), is described. The copolymers with well-defined structures were synthesized by atom transfer radical polymerization (ATRP) and once unprotected, were used for the efficient surface functionalization of silver.