What Techniques are Used for Imaging Nanoparticles?
Several advanced techniques are employed for imaging nanoparticles, each with its strengths and limitations:
1. Transmission Electron Microscopy (TEM): TEM provides high-resolution images by transmitting electrons through a thin sample. It can reveal the internal structure of nanoparticles, making it ideal for studying their crystallography and morphology.
2. Scanning Electron Microscopy (SEM): SEM generates images by scanning a focused electron beam across the surface of a sample. It is particularly useful for examining surface topography and composition.
3. Atomic Force Microscopy (AFM): AFM uses a cantilever with a sharp tip to scan the surface of a sample. It can provide three-dimensional surface profiles and measure mechanical properties at the nanoscale.
4. Dynamic Light Scattering (DLS): DLS measures the size distribution of nanoparticles in suspension by analyzing the scattering of light. It is commonly used for characterizing colloidal nanoparticles.
5. Fluorescence Microscopy: This technique uses fluorescent markers to visualize nanoparticles. It is especially useful in biological applications where nanoparticles are used as contrast agents or drug carriers.
