School of Chemistry and Chemical Engineering, Southeast University, Jiangning, Nanjing, 211189, PR China.
Clin Chim Acta. 2010 Dec 14;411(23-24):1969-75. doi: 10.1016/j.cca.2010.08.012. Epub 2010 Aug 13.
The detection of Epstein-Barr virus-derived latent membrane protein 1 (LMP-1) is essential for understanding its contribution to the development of malignancy in epithelial cells and the early screening of nasopharyngeal carcinoma tumors. It is important to explore novel means for enhancing detection sensitivity of LMP-1.
The current strategy for enhancing sensitivity is based on signal amplification of LMP-1/cadmium telluride (CdTe) quantum dots (QDs) functionalized silica nanosphere labels (Si/QD/Ab2). Si/QD/Ab2 was fabricated by covalently binding LMP-1 antibody (denoted Ab2) to CdTe QDs, which have been previously coated onto the surface of silica nanoparticles with EDC Chemistry. The as-prepared Si/QD/Ab2 label can be brought to a modified gold slice by a "sandwiched" immunoreaction, which was confirmed by SEM images and detected by square wave voltammetry (SWV).
The amount of captured Si/QD/Ab2 by sandwiched immunoreaction was related to the concentration of LMP-1 in the incubation solution. The calibration range for LMP-1 detection was found to be 0.001 to 10 ng/ml with a correlation coefficient of 0.9897 and the lowest detectable concentration of 0.001 ng/ml. Compared with traditional sandwich immunoassay, the detection sensitivity of presented approach was enhanced largely due to the large surface area of silica nanoparticle carriers, which increased in CdTe QDs loading per sandwiched immunoreaction.
The ease of functionalization, good monodispersed sizes and uniformity of the silica nanoparticles allows the QDs coated silica nanospheres to be highly suited for immunological labeling of trace protein analysis. The proposed method is simple, selective, reproducible, and can be extended to study protein-protein, peptide-protein, and DNA-protein interaction.
检测 Epstein-Barr 病毒衍生的潜伏膜蛋白 1（LMP-1）对于了解其在上皮细胞恶性肿瘤发展中的作用以及对鼻咽癌肿瘤的早期筛查至关重要。探索提高 LMP-1 检测灵敏度的新方法非常重要。
目前提高灵敏度的策略是基于 LMP-1/碲化镉（CdTe）量子点（QDs）功能化硅纳米球标记物（Si/QD/Ab2）的信号放大。Si/QD/Ab2 通过将 LMP-1 抗体（Ab2）共价结合到 CdTe QDs 上制备，CdTe QDs 先前已通过 EDC 化学涂层到硅纳米粒子的表面上。通过“夹心”免疫反应可以将制备的 Si/QD/Ab2 标记物带到修饰的金片上，这通过 SEM 图像和方波伏安法（SWV）得到证实。
夹心免疫反应中捕获的 Si/QD/Ab2 的量与孵育溶液中 LMP-1 的浓度有关。发现 LMP-1 检测的校准范围为 0.001 至 10 ng/ml，相关系数为 0.9897，最低检测浓度为 0.001 ng/ml。与传统的夹心免疫测定相比，由于硅纳米颗粒载体的表面积大，每个夹心免疫反应中 CdTe QDs 的载量增加，因此所提出的方法大大提高了检测灵敏度。
硅纳米球的功能化容易、良好的单分散性和均一性使涂覆 CdTe QDs 的硅纳米球非常适合痕量蛋白质分析的免疫标记。该方法简单、选择性好、重现性好，可扩展用于研究蛋白质-蛋白质、肽-蛋白质和 DNA-蛋白质相互作用。
