Photochemistry and Spectroscopy

Abstract

Photochemical reaction, a chemical reaction initiated by the absorption of energy in the form of light. The consequence of molecules’ absorbing light is the creation of transient excited states whose chemical and physical properties differ greatly from the original molecules. These new chemical species can fall apart, change to new structures, combine with each other or other molecules, or transfer electrons, hydrogen atoms, protons, or their electronic excitation energy to other molecules. Excited states are stronger acids and stronger reductants than the original ground states. Spectrometric biosensors, which depend on the changes of photophysical properties, have been found to be particularly attractive, because of the fact that spectrometry is the most studied and most widely used technology. Now, with the development of nanoscience and nanotechnology, many nano-inspired spectrometric biosensors, including colorimetric sensors, fluorescent sensors, chemiluminescence sensors, electro chemiluminescence sensors, surface-enhanced Raman scattering sensors, and dynamic light scattering sensors, have emerged. These biosensors not only hold the inherent advantages of spectrometric analysis, but show their own unique advantages from the nanomaterials at the same time.