Title : Multiple phase separation of carbon dot-based fluorescent coacervate
Abstract:
While the molecular mechanisms and mesoscopic properties of coacervates as a proto-cells formed from charged components have been extensively studied, the assembly and stabilization of nonionic coacervates remain largely unexplored. Our research investigates the pH-responsive behavior of a novel carbon dot-based fluorescent coacervate characterized by multiple phase separations. Remarkably, this coacervate was formed when a clear ethanolic solution of carbon dots was introduced to water, resulting in immediate turbidity due to coacervate formation driven by liquid-liquid phase separation. This intriguing phenomenon was meticulously monitored using optical microscopy, providing valuable insights into the initial stages of Coacervate development. Under confocal microscopy, the Coacervate revealed a core-shell structure. The synthesized carbon polymer dots consist of two distinct regions: one exhibiting low viscosity and another with high viscosity. This differential viscosity facilitates the formation of core-shell droplets, where the darker, fluorescent core is encapsulated by the less viscous shell. Notably, while existing literature discusses various types of coacervates, our synthesized coacervate represents the first instance of a self-fluorescent coacervate. Upon exposure to varying pH levels, we observed significant phase transitions. Our findings highlight the dynamic behavior of this carbon dot-based coacervate under different environmental conditions, particularly its responsiveness to pH changes. Fluctuations in pH resulted in marked alterations in fluorescence intensity and phase behavior, suggesting promising applications in biomedical imaging for real-time monitoring and detection. In summary, this study elucidates the complex interplay between pH and coacervate stability while setting the stage for future investigations into nonionic coacervates. By advancing our understanding of these systems, we pave the way for innovative applications in nanotechnology and material science, particularly in developing responsive materials that can adapt to environmental changes.
