Fluorescence Measurement

Fluorescence is the absorption and emission of light of two different frequencies. Typically, a lower wavelength of incident light is absorbed from one direction, and a higher wavelength of light is emitted in all directions. Fluorescent molecules absorb light at a certain wavelength and emit at another. With a known incident light wavelength, samples can be identified by their fluorescent emission spectra. Because fluorescence occurs on a molecular scale, it is the only spectroscopic technique capable of identifying single molecules. 

Advantages of Absorbance

• High sensitivity - Very low sample concentration levels can be detected
• Quantitative results - In most cases, fluorescence signal is proportional to concentration and responds to concentration changes within picoseconds
• Non-destructive measurements - Unlike some techniques, fluorescence is non-destructive to both liquid and solid samples