Water-soluble quantum dots (QDs) as a kind of novel biological fluorescent probe, in immune biology and clinical examination in science and other research has broad application prospects. And comparing with narrow excitation,broad emission and narrow Stokes shift of traditional organic dyes,they possess tunable fluorescence emission,high photostability and attractive spectrum with almost symmetrical narrow emission and broad excitation; and they are scores of times as bright as the organic dyes at least.Thi...