The Study On The Mechanism Of The Interaction Between CdTe Nanocrystals And Phenylalanine

Nanocrystals,composed byⅡB,ⅥA orⅢA,ⅤA elements, can produce fluorescence after accepting photons. The achievement of desired particle sizes over the largest possible range, narrow size distribution, photostability, desired surface properties, and high luminescence quantum yields are parameters that are considered to be characteristics of an ideal fluorescence probe applied to super sensitive detect in the field of molecule biology and bioengineering. Nanocrystals are of great interest for extensive applications in labeling multi-cell and multi-molecule in cell under the physiological condition of active cell.In this paper, interaction between CdTe nanocrystal and Phenylalanine is investigated in order to find the mechanism of nanocrystals reacting with some biomolecules such as protein and enlarge the application of nanocrystals in biomedicine field, especially in immunity detectction.Main researches as bellow:1. CdTe nanocrystals with high photofluorescence(PL) intensity capped with thioglycolic acid in aqueous are synthesized. It can be seen from PL spectra that the size distribution is narrow and the diameter is homogeneous.2. CdTe can combine with Phenylalanine (Phe), the reaction condition has great effect on the PL intensity of conjugates. The results indicate that the highest PL intensity of CdTe-Phe conjugates is obtained when the refluxing time is 30min, the pH valus is 7.80 and the molar ratio of Cd/Phe is 2:1.3. The PL intensity of CdTe- Aniline conjugate is the highest in three conjugates while for CdTe-Alanine is the lowest, but it is still more than that of CdTe itself. After laying several days under low temperature PL intensity of CdTe- Aniline conjugate attenuates sharply whereas the PL intensity of CdTe-Phe decrease slowly. One conclusion is that the electron-donating group, electron-drawing group and conjugated structure of phenyl can make greet influence on the PL intensity. The other is that the cooperative action of–NH2 and–COOH and the hydrogen bond intermolecular can affect the stability of the conjugates.4. The mechanism of the conjugation between CdTe and Phenylalanine has been investigated by IR spectrum and PL spectrum analysis.