- Free Articles
- Carbohydrate-Metal Complexes: Structural Chemistry of Stable Solution Species Glycoscience
- Biomedicine of Enkephalin-Derived Analgesics Glycoscience
- Applications of Computational Methods to Simulations of Proteins Dynamics Handbook of Computational Chemistry
- Quantum Chaos Encyclopedia of Complexity and Systems Science
- Astrology of Mandalas Encyclopedia of Psychology and Religion
- More Free Articles
Photosenitization can be defined as a process in which light absorption by a photosensitizer molecule leads to a photophysical or photochemical change in a second molecule or system.
The scientific term sensitization referred originally to the process by which a photographic film or plate was made more sensitive to particular wavelengths of light. The history of dye-sensitization began in 1873 with the discovery by Hermann Wilhelm Vogel (1834-1898) that the sensitivity of silver halide photographic plates to green and red light was greatly enhanced by the presence of dyes in the photographic emulsion. Using a ‘cocktail’ of different coloured dyes, Vogel was able to achieve tone balance in black and white photographs . It is now generally accepted that the photo-excited state of the dye injects electrons into the silver halide, leading to the formation of silver atoms. The oxidized dye can be regenerated by electron transfer from a 'super-sensitizer'