Laboratories for Nanoscience and Nanotechnology Research, Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam, Andhra Pradesh, India.
Andhra Med Tech Zone, Hill No. 2, IT Park Madhurwada, Rushikonda, Vishakhapatnam, Andhra Pradesh 530045, India.
Sci Adv. 2018 Nov 21;4(11):eaar6280. doi: 10.1126/sciadv.aar6280. eCollection 2018 Nov.
We have engineered streptavidin-labeled fluorescent gold nanoclusters to develop a gold nanocluster immunoassay (GNCIA) for the early and sensitive detection of HIV infection. We performed computational simulations on the mechanism of interaction between the nanoclusters and the streptavidin protein via in silico studies and showed that gold nanoclusters enhance the binding to the protein, by enhancing interaction between the Au atoms and the specific active site residues, compared to other metal nanoclusters. We also evaluated the role of glutathione conjugation in binding to gold nanoclusters with streptavidin. As proof of concept, GNCIA achieved a sensitivity limit of detection of HIV-1 p24 antigen in clinical specimens of 5 pg/ml, with a detection range up to1000 pg/ml in a linear dose-dependent manner. GNCIA demonstrated a threefold higher sensitivity and specificity compared to enzyme-linked immunosorbent assay for the detection of HIV p24 antigen. The specificity of the immunoassay was 100% when tested with plasma samples negative for HIV-1 p24 antigen and positive for viruses such as hepatitis B virus, hepatitis C virus, and dengue. GNCIA could be developed into a universal labeling technology using the relevant capture and detector antibodies for the specific detection of antigens of various pathogens in the future.
我们设计了链霉亲和素标记的荧光金纳米簇，以开发一种用于早期和灵敏检测 HIV 感染的金纳米簇免疫分析（GNCIA）。我们通过计算机模拟研究了纳米簇与链霉亲和素蛋白之间的相互作用机制，并表明与其他金属纳米簇相比，金纳米簇通过增强 Au 原子与特定活性位点残基之间的相互作用，增强了与蛋白质的结合。我们还评估了谷胱甘肽缀合在与链霉亲和素结合到金纳米簇中的作用。作为概念验证，GNCIA 在临床标本中实现了 HIV-1 p24 抗原的检测灵敏度下限为 5 pg/ml，线性剂量依赖性检测范围高达 1000 pg/ml。与酶联免疫吸附试验（ELISA）相比，GNCIA 检测 HIV p24 抗原的灵敏度和特异性均提高了三倍。当用 HIV-1 p24 抗原阴性但乙型肝炎病毒、丙型肝炎病毒和登革热等病毒阳性的血浆样本进行测试时，免疫分析的特异性为 100%。GNCIA 未来可开发成一种通用标记技术，使用相关的捕获和检测抗体，用于特异性检测各种病原体的抗原。
