When it comes to monolayer analysis, one is faced with the extremely small quantities of material available, which renders many conventional spectroscopic approaches such as NMR inapplicable. Fortunately, there are techniques that are sufficiently sensitive to analyze molecular monolayers, such as scanning probe microscopy (SPM) , UV-vis spectroscopy , and TERS . SPM provides topographic and electronic structure information of the analyte but very limited chemical information. UV-vis spectroscopy provides useful information from the maximum absorption wavelength of molecules, and TERS gives detailed chemical information if the signals obtained can be assigned with the help of theoretical calculations.