In this study, we present for the first time, a solvent-free synthesis of polystyrene (PS) nanoparticles via radiofrequency (RF) magnetron-based gas aggregation cluster source (GAS). A PS target, 81 mm in diameter and 4 mm thickness, is bombarded by high-energy plasma species, mainly ions generated by the magnetron, leading to the ejection of atoms, molecules, or molecular fragments from the target. The ejected species then travel and condense onto the surrounding surfaces. The PNPs were synthesized under constant pressure of 164 Pa and a constant flow of 40 sccm of argon for 30 minutes. The effect of power was investigated on the morphology and chemical characteristics of the synthesized PNPs. The PNPs synthesized at lower power (40 W) exhibited spherical morphology with a diameter of approximately 100 nm, while higher powers (60 and 80 W) led to a cauliflower-like morphology marginally larger than the 40 W particles. For further comprehensive analysis of the formed PNPs advanced techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FT-IR) were employed to provide insight into the elemental composition and surface functional groups. Due to particles appearing transparent in the scanning-electron microscopy (SEM) images, ultraviolet-visible spectroscopy was utilized to elucidate optical properties and the potential application of the synthesized PNPs in optoelectronic devices.