One-step photochemical synthesis of gold-polymer nanohybrids with engineered morphologies and catalytic activity

Thermoresponsive gold-polymer nanohybrids are promising functional materials, but their synthesis and structural control often require complex multistep processes. Herein, we report a one-step photochemical synthesis that enables the rapid formation of thermoresponsive hybrid nanogels via simultaneous polymerization, crosslinking, and reduction within 10 minutes. The key strength of this approach lies in its structural versatility and control. By tuning the reagent concentration and temperature, nanogels with distinct morphologies and internal architectures were obtained. Notably, this single-step method enables the direct formation of both conventional solid nanogels and sophisticated hollow spherical structures where gold nanoparticles are embedded within the thermoresponsive polymer shell. The formation mechanism of these hybrid hollow structures was systematically investigated by electron microscopy and small-angle X-ray scattering analyses for samples collected at various irradiation times. Furthermore, the thermoresponsive catalytic activity of the resulting nanogels was demonstrated via the reduction of 4-nitrophenol. This highlights how the readily adjustable internal structure and composition directly translate to functional properties, confirming this facile strategy as a promising route for designing hybrid nanomaterials with tailored structural complexity and function.