From Chromic Phenomena: Technological Applications of Colour Chemistry

3.5 Fluorescence

Fluorescence from organic materials is a very important phenomenon that is exploited in a broad range of application areas. These include their use in the dyeing of synthetic textile fibres, as daylight fluorescent pigments in a wide variety of media, including inks, paints and plastics, in detection of flaws in materials, in dye lasers, as solar collectors, in many very important analytical methodologies and in biological and medical applications in both detection and diagnosis of diseases, in assays and in display applications such as electroluminescence (see section 3.8) and in molecular electronics.17

Some of the theoretical aspects of fluorescence have already been discussed alongside phosphorescence in section 3.2 and shown schematically in Figure 3.1. In organic fluorophores, especially dyes, excitation from the ground level S 0 to the first excited state S 1 is generally a ?- ?* electronic transition. During the extremely short time (1 10 10 ?9 s) that the excited molecule spends in the various higher vibrational levels of the excited S 1 state it loses energy by various actions in its molecular environment. If the molecule returns to the ground state emitting the radiation as visible light it exhibits fluorescence, which, due to the loss of vibrational energy, is at a longer wavelength than the initially absorbed light. As already stated this difference in wavelength between absorption and emission is known as the Stokes shift. In general the Stokes shift is in the region of 30 70 nm but can...

Products & Services
Fluorometers measure the amount of fluorescent radiation produced by a sample exposed to monochromatic radiation.
Spectrometer Repair Services
Spectrometer repair services provide a cost-effective solution for refurbishment and repair for all types of spectrometers and spectrometer system components.
HPLC Detectors
High performance liquid chromatograph (HPLC) detectors pass a beam of light through a column effluent as the fluid passes through a low-volume flow cell. Variations in light intensity are recorded and a chromatograph is generated.
High Performance Liquid Chromatographs (HPLC)
High performance liquid chromatographs (HPLC) use a liquid mobile phase to separate the components of a mixture. The components are dissolved in a solvent and forced to flow through a chromatographic column under high pressure.
Microplate Readers
Microplate readers are designed to scan, analyze and obtain numerical results from chemical reactions conducted within microplates.

Topics of Interest

3.6 Chemiluminescence Chemiluminescence is the production of light by chemical substances without the help from other energy sources; in effect it is the conversion of energy stored in chemical bonds...

3.2 Luminescent Pigments As stated above, there is no intention to provide any detailed discussions of the theory of luminescent phenomena; however, a basic understanding is essential. A simplified...

Fluorescence depolarization or fluorescence anisotropy can be observed when a fluorophore emits light of different intensities depending on the axes of polarization. When a molecule is excited by the...

4.1 Introduction The excited state produced by the interaction of a molecule with light can lose or transfer its energy in various ways.1 Return to the ground state can be accompanied by the emission...

It is difficult to overestimate the impact fluorescence imaging has had on life sciences. Fluorescence has advanced the field dramatically, and has become the basis for numerous bio-imaging methods...