Laboratories for Nanoscience and Nanotechnology Research, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, 515134, Andhra Pradesh, India.
Laboratory of Molecular Virology, Centre for Biologics Evaluation and Research (CBER), US Food and Drug Administration, Bldg. 72, White Oak Campus, 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA.
Sci Rep. 2017 Aug 2;7(1):7149. doi: 10.1038/s41598-017-07299-1.
We have engineered streptavidin labelled Europium doped fluorescent silica nanoparticles which significantly increased sensitivity without compromising the specificity of the immunoassay. As a proof of concept, a time resolved fluorescence based sandwich immunoassay was developed to detect HIV-1 p24 antigen in clinical specimens. The detection range of the silica nanoparticle based immunoassay (SNIA) was found to be between 0.02 to 500 pg/mL in a linear dose dependent manner. SNIA offers 1000 fold enhancement over conventional colorimetric ELISA. Testing of plasma samples that were HIV negative showed no false positive results in the detection of HIV-1 p24 antigen. This highly sensitive p24 assay can help improve blood safety by reducing the antibody negative window period in blood donors in resource limited settings where nucleic acid testing is not practical or feasible. This technology can also be easily transferred to a lab-on-a-chip platform for use in resource limited settings and can also be easily adopted for the detection of other antigens.
我们已经设计出了表面带有生物素标签的 Eu 掺杂荧光硅纳米颗粒，这在不影响免疫测定特异性的情况下显著提高了检测的灵敏度。作为概念验证，我们开发了一种基于时间分辨荧光的三明治免疫分析法，用于检测临床标本中的 HIV-1 p24 抗原。结果表明，硅纳米颗粒免疫分析法（SNIA）的检测范围在 0.02 到 500pg/mL 之间呈线性剂量依赖性。SNIA 比传统的比色 ELISA 检测方法提高了 1000 倍。对 HIV 阴性的血浆样本进行检测，在检测 HIV-1 p24 抗原时没有出现假阳性结果。这种高灵敏度的 p24 检测方法可以通过减少资源有限地区献血者的抗体阴性窗口期，从而提高血液安全性，在这些地区，核酸检测不实际或不可行。这项技术也可以很容易地转移到实验室芯片平台上，用于资源有限的地区，也可以很容易地用于检测其他抗原。
