Enhanced Fluorescence Imaging with Ultra-Bright Pervoskite Labels

Fluorescent labeling is essential for visualizing cellular structures and tracking dynamic processes in biological research. Traditional fluorescent labels include molecular dyes, quantum dots, proteins and nanoparticles. Here, we explore the potential of perovskite nanocrystals (CsPbX₃, PNCs) for labeling cells. Over the past decade, lead-halide PNCs have gained significant attention for their exceptional optical properties, including strong light absorption, high photoluminescence and tunable bandgap. To synthesize these PNCs, we utilized both the hot-injection and ligand-assisted reprecipitation (LARP) methods. The hot-injection technique ensures uniform size distribution, while LARP offers greater simplicity and versatility. However, PNCs are highly moisture-sensitive, limiting their stability in aqueous environments. To address this, we encapsulated them with hydrophobic polymers such as silica, poly(lactic-co-glycolic acid), and polystyrene, extending their stability in aqueous solutions from hours to years. These nanoparticles approximately ~100 nm in size, are efficiently internalized by cells. The bright, polymer-coated PNCs were used to label both cancer and stem cells, demonstrating their potential as high-contrast fluorescent probes for bioimaging applications.