ABSTRACT
Fluorescence is popular in carbohydrate, protein, and DNA arrays; cell imaging; and single molecule detection because of its sensitivity. To achieve high sensitivity, ϐluorophores possessing high quantum yields are necessary. However, most analytes do not ϐluoresce strongly. In order to overcome this shortage, techniques based on ϐluorescence quenching and surface-enhanced ϐluorescence using novel metal materials have been applied. Fluorescence quenching and enhancements are both dependent on the distance of ϐluorophores from the metal surface; quenching usually occurs at a distance no greater than 50 Å while ϐluorescence enhancement commonly takes place at a distance between 70 and 100 Å. In addition to distance, the nature, size, and shape of metal materials are important parameters for ϐluorescence quenching and enhancement. With advanced nanotechnology, researchers have demonstrated techniques
entailing ϐluorescence quenching and enhancement using novel metal nanomaterials for the sensitive analysis of proteins, DNA, and small solutes.
