PEGylated Gold Nanoparticles Grafted with N-Acetyl-L-Cysteine for Polymer Modification

The subjects of this work were the enhancement and determination of the stability and other properties of gold nanoparticles (AuNPs) in an aqueous solution, gold nanoparticle immobilization, and further surface grafting on polyethylene naphthalate (PEN). Gold nanoparticles in PEG with a subsequent water solution addition were prepared using cathode sputtering; for the subsequent surface activation, two different solutions were used: (i) sodium citrate dihydrate (TCD) and (ii) N-acetyl-L-cysteine (NALC). The aim of this work was to study the effect of the concentration of these solutions on AuNPs stability, and further, the effect of the concentration of gold nanoparticles and their morphology, and to describe the aging process of solutions, namely, the optical properties of samples over 28 days. Stabilized AuNPs were prepared in an N-acetyl-L-cysteine (NALC) system and subsequently immobilized with NALC. The surface chemistry modification of AuNPs was confirmed using HRTEM/EDS. Gold nanoparticles were successfully immobilized with NALC. Grafting of the modified PEN from a solution of colloidal gold stabilized in the PEG-H₂O-NALC system led to the polymer surface functionalization.