To measure the size of carbon dots in liquid form, you can use techniques such as Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM):
Dynamic Light Scattering (DLS): This technique measures the size distribution of particles in a liquid by analyzing the fluctuations in light scattering due to Brownian motion. It's a quick and non-invasive method.
Transmission Electron Microscopy (TEM): This method provides high-resolution images of the carbon dots, allowing you to directly measure their size. However, it requires more preparation and is not as quick as DLS.