Simultaneous functionalization of gold nanoparticles with folic acid and polyethyleneglycol

Background and Objectives: This article presents a comprehensive hydrothermal synthesis for the simultaneous modification of gold nanoparticles using folates and polyethyleneglycol containing terminal amino groups. This methodology ensures a high degree of functionalization of gold nanoparticles, as evidenced by changes in the ζ-potential and modification of luminescent characteristics. This article demonstrates the one-step synthesis of luminescent gold nanostructures from folic acid and polyethyleneglycol, and examines the influence of the polymer length and the number of amino groups on the optical properties of the synthesized structures. Materials and Methods: Folic acid was chosen due to its ability to act as targeting ligands, specifically interacting with cell membrane receptors. Polymers based on polyethyleneglycol with terminal amino groups were chosen to increase the circulation time of nanoparticles in biological environments due to their high biocompatibility and ability to form stable complexes with functional groups. The use of hydrothermal synthesis is driven by its ability to provide controlled modification of nanoparticles under high temperatures and pressure. This facilitates the uniform distribution of functional groups and increases the stability of the resulting composite materials. Results: The use of the hydrothermal synthesis method is able to provide controlled modification of nanoparticles under the influence of high temperatures and pressure. This contributes to a uniform distribution of functional groups and increases the stability of the resulting composite materials. Conclusions: Thus, the feasibility of functionalizing AuNPs with folates and polymers via a single-step hydrothermal synthesis was demonstrated, and the influence of the polymer length and the number of amino groups on the optical properties of the synthesized structures was studied. Modified AuNPs can be used for selective nanoparticle internalization into tumor cells. Future studies will demonstrate the stability and limited targeting of these conjugates in vivo. These results will be an important stepping stone for future research in cancer cell imaging, tumor ablation, and drug development.