Single molecule spectroscopy

Single molecule spectroscopy is a single molecule detection technique used to detect, measure and visualize single molecules using light. Since even most very large molecules are much too small to be seen with a light microscope, modifications to the molecule are necessary. The most common visualization technique is to attach fluorophores to the target molecule.

History
Single molecule spectroscopy began in 1976, when Hirschfeld tagged a single antibody with 80-100 fluorophores and was able to see the molecule under a microscope. In 1990, the first detection of a single fluorophore was published.