以传统的戊二醛交联的方法实现了聚丙烯酸包覆的CdSe/ZnS量子点和人IgG蛋白分子的偶联,同时研究了偶联过程对量子点发光性能的影响。通过琼脂糖凝胶电泳技术证明量子点和蛋白分子偶联成功。通过稳态光谱和时间分辨光谱研究了偶联过程对量子点荧光性质的影响。发现偶联到量子点表面的戊二醛分子能够破坏量子点的表面从而增加其表面缺陷,使量子点发光效率降低;上述产物进一步与人IgG偶联增强了量子点的荧光强度,这是由于连接到量子点上的蛋白分子修复了量子点的表面,从而降低了表面缺陷所致。
Conjugates of human IgG and CdSe/ZnS quantum dots (QDs) capped with an amphiphilic poly (acrylic acid) polymer modified with poly (ehylene glycol) amine were synthesized by a glutaraldehyde (Cho) cross-linking procedure. The IgG-QD assemblies form in this reaction, as evidenced by gel electropho: resis. The key function of QD bioconjugates is to fluoresce readily and remain stable in biological conditions in order to allow for efficient bioapplication. However, the photoluminescence (PL) properties of QDs are sensi- tive to their environment, so it is particular important to study the mechanisms of the PL change of QDs linked to biomolecules. The effect of cross-linking processes on the PL of QDs was studied by means of steady-state and time-resolved photoluminescence spectroscopy. Attachment of Cho on the surface of QDs results in a sig- nificant decrease of QD emission due to the increase of surface defects with Cho destroying the surface of QDs. Attachment of IgG on the surface of QDs results in a significant increase of QD-Cho emission, which is attributed to the conjugation of IgG to QD modifying the surface of CdSe/ZnS QDs.