Scalable Purification of Gold Nanocubes via Centrifugal Depletion-Induced Flocculation Jiho Kim Gwangju Institute of Science and Technology

Abstract

Large-scale synthesis of metal nanoparticles often leads to considerable heterogeneity in size and shape, which limits reproducibility and reduces reliability in plasmonic applications. To address this challenge, we developed a centrifugal depletion-induced flocculation (CDF) method that combines controlled centrifugation with depletion interactions, enabling rapid and efficient purification of gold nanocubes (AuNCs). Unlike conventional sedimentation-based approaches, CDF achieves high particle uniformity while significantly reducing processing time. Systematic optimization of nanoparticle concentration, centrifugal force, and flocculation duration resulted in recovery efficiencies above 98% and yields of 98–99% for 60 nm AuNCs. The method also proved effective for nanocubes of different sizes and larger batch volumes, confirming its scalability. The purified AuNCs exhibited superior monodispersity and shape uniformity, providing improved control over plasmonic resonances. These advantages establish CDF as a versatile purification strategy for applications in high- performance optical sensing and integrated nanophotonic devices. MS/CH 20241112 Jiho Kim (김지호), Scalable Purification of Gold Nanocubes via Centrifugal Depletion- Induced Flocculation (원심력 고갈 유도 응집을 통한 금 나노큐브의 확장 가능 한 정제). Department of Chemistry, 2025. 32 p. Prof. Jeong-Eun Park