Hua Xiao-Feng, Liu Tian-Cai, Cao Yuan-Cheng, Liu Bo, Wang Hai-Qiao, Wang Jian-Hao, Huang Zhen-Li, Zhao Yuan-Di
Key Laboratory of Biomedical Photonics of Ministry of Education-Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, HuBei, People's Republic of China.
Anal Bioanal Chem. 2006 Nov;386(6):1665-71. doi: 10.1007/s00216-006-0807-5. Epub 2006 Oct 11.
Water-soluble quantum dots (QDs) were used to label goat anti-human immunoglobulin antibodies (Abs), and the labeling process was characterized by column purification. The QDs obtained in organic solvent were modified with mercaptoacetic acid (MAA) and became water-soluble. These water-soluble QDs were linked to the antibodies using the coupling reagents ethyl-3-(dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The linking process was shown to be effective by ultra-filter centrifugation and column purification. After comparing the quantities of Abs and water-soluble QDs involved in the linking reaction via column purification, it was found that a molar Abs:QD ratio of >1.2 resulted in most of the water-soluble QDs becoming covalently linked to the Abs. The circular dichroism (CD) spectra of Abs and QD-Ab conjugates were very similar to each other, indicating that the secondary structure of Abs remained largely intact after the conjugation. Finally, antigen (Ag)-antibody (Ab) recognition reactions perfomed on the surface of a glass slide showed that the conjugate retained the activity of Abs. This work lends support to the idea of linking biomolecules to QDs, and thus should aid the application of QDs to the life sciences.
水溶性量子点（QDs）被用于标记山羊抗人免疫球蛋白抗体（Abs），标记过程通过柱纯化进行表征。在有机溶剂中获得的量子点用巯基乙酸（MAA）进行修饰，从而变得具有水溶性。这些水溶性量子点使用偶联剂1-乙基-3-(3-二甲基氨基丙基)碳二亚胺（EDC）和N-羟基琥珀酰亚胺（NHS）与抗体相连。通过超滤离心和柱纯化表明连接过程是有效的。通过柱纯化比较连接反应中所涉及的抗体和水溶性量子点的量后，发现抗体与量子点的摩尔比>1.2会导致大多数水溶性量子点与抗体共价连接。抗体和量子点-抗体缀合物的圆二色性（CD）光谱彼此非常相似，表明缀合后抗体的二级结构基本保持完整。最后，在载玻片表面进行的抗原（Ag）-抗体（Ab）识别反应表明缀合物保留了抗体的活性。这项工作支持了将生物分子与量子点相连的想法，因此应该有助于量子点在生命科学中的应用。
