A One-Step Plasma Assisted Synthesis of Gold Nanoparticles and Simultaneous Linker-Free Conjugation with Nestin: An In Vitro Study of Cellular Toxicity

We present a method for conjugating antigens to gold nanoparticles (GNPs) during their synthesis via gas plasma, eliminating the need for chemical linkers and significantly speeding up the process (taking only 15 min). This fast, linker-free method produces biocompatible and stable GNPs, with potential for immunotherapy applications, such as antigen and antibody conjugation and drug delivery. We demonstrate the conjugation of the antigen Nestin (NES), a tumor marker, to GNPs using two approaches. The first method involves synthesizing GNPs with citrate, followed by NES conjugation via plasma. The second method synthesizes and conjugates GNPs to NES simultaneously using plasma treatment. Conjugation was confirmed by <i>Enzyme-Linked Immunosorbent Assay</i>, <i>Zeta-sizer</i>, <i>UV-vis spectroscopy</i>, and <i>Transmission Electron Microscopy</i>. In addition, the toxicity of the prepared samples was investigated in vitro using peripheral blood mononuclear cells (PBMCs) and <i>flow cytometry</i>, which proved the nontoxicity of the samples.