Nanoparticles are crucial components for a new generation of technological and biomedical applications, such as displays and vaccines. This project develops advanced microscopy techniques to analyze various types of nanoparticles on an individual particle basis. By combining laser-scanning, fluorescence microscopy, 3D piezo-tracking, and electrophoresis, it provides detailed information on each particle's size, charge, and number of emitting molecules. Targeted applications range from mRNA-carrying lipid nanoparticles and virus-like particles to CdSe/CdS quantum dots and even single molecules. This work is expected to enhance our understanding of nanoparticle properties, ultimately enabling improved and innovative applications.