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.
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.