Real-time, non-destructive monitoring of the aggregation behavior of silver nanoparticles using nano-impact electrochemistry†

Silver nanoparticles (AgNPs) are widely used in daily life, with their aggregation behavior greatly impacting their application potential. Thus, studying the aggregation of AgNPs is crucial for their practical applications. Nano-impact electrochemistry (NIE) has gained significant attention due to its rapid, cost-effective, and in situ analysis capabilities at the single-nanoparticle level. In this study, we propose a method for real-time and non-destructive monitoring of the rapid aggregation behavior of AgNPs within 10 minutes in chlorine-containing acidic media using NIE, a condition particularly relevant to biological systems, such as the antibacterial applications of AgNPs. Under this environment, a thin AgCl layer forms on the surface of AgNPs, interconnecting them and facilitating their aggregation. Therefore, the aggregation behavior of AgNPs can be analyzed by quantifying the electrochemical reduction of the AgCl coating in NIE measurements, allowing insights into aggregation kinetics by tracking the number of aggregated AgNPs over time. This real-time, non-destructive approach to monitoring AgNP aggregation deepens our understanding of their physicochemical properties and dynamic behavior in biological environments, offering valuable insights for optimizing their application in practical settings.