NanoTech Absorbance Spectroscopy
Most people in the scientific community understand that size and shape dictate the absorption and emission properties of quantum dots. This is why optical properties of quantum dots can be easily tuned, leading to their utilization in countless applications ranging from optoelectronics to molecular biology. Not as widely known is that the size-dependent absorption properties are not unique to quantum dots. Similar behavior can be observed in all types of nanostructures, including thin films, carbon nanotubes, and fullerenes. Therefore, the absorbance spectra can serve as a valuable tool for determining average particle size and other physiochemical properties. To better understand how absorption spectroscopy is used for nanoparticle characterization, this application note will briefly explain the underlying physics behind size induced quantum energy levels, including how they differ from traditional molecular absorption. Then we will go on to provide examples of published nanoparticle characterization methodologies and discuss typical experimental set-ups.