College of Veterinary Medicine, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China , Yangzhou University , Yangzhou 225009 , China.
Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary medicine , Nanjing Agricultural University , Nanjing 210095 , China.
ACS Sens. 2018 Oct 26;3(10):2175-2181. doi: 10.1021/acssensors.8b00785. Epub 2018 Oct 5.
Cryptosporidium parvum ( C. parvum) is a highly potent zoonotic pathogen, which can do significant harm to both human beings and livestock. However, existing technologies or methods are deficient for rapid on-site detection of water contaminated with C. parvum. Better detection approaches are needed to allow water management agencies to stop major breakouts of the pathogen. Herein, we present a novel detection method for cryptosporidium in a tiny drop of sample using a magnetic nanoparticle (MNP) probe combined with dark-field microscopy in 30 min. The designed MNP probes bind with high affinity to C. parvum, resulting in the formation of a golden garland-like structure under dark-field microscopy. This MNP-based dark-field counting strategy yields an amazing PCR-like sensitivity of 8 attomolar (aM) (5 pathogens in 1 μL). Importantly, the assay is very rapid (∼30 min) and is very simple to perform as it involves only one step of mixing and magnetic separation, followed by dropping on a slide for counting under dark-field microscope. By combining the advantages of the specific light-scattering characteristic of MNP probe under dark field and the selective magnetic separation ability of functionalized MNP, the proposed MNP-based dark-field enumeration method offers low cost and significant translational potential.
微小样本中隐孢子虫的快速磁纳米颗粒探针检测法
隐孢子虫（C. parvum）是一种高潜能的人畜共患病病原体，对人类和家畜都有严重危害。然而，现有的技术或方法在快速现场检测污染水中的隐孢子虫方面存在不足。需要更好的检测方法来帮助水务管理部门阻止该病原体的大规模爆发。本研究提出了一种利用磁纳米颗粒（MNP）探针结合暗场显微镜在 30 分钟内检测微小样本中隐孢子虫的新方法。设计的 MNP 探针与隐孢子虫具有高亲和力，在暗场显微镜下形成类似金色花环的结构。基于 MNP 的暗场计数策略具有令人惊叹的 PCR 样灵敏度，可达 8 皮摩尔（aM）（5 个病原体在 1μL 中）。重要的是，该检测方法非常快速（约 30 分钟），操作非常简单，仅需混合和磁分离一步，然后滴在载玻片上在暗场显微镜下进行计数。通过结合暗场下 MNP 探针的特异性光散射特性和功能化 MNP 的选择性磁分离能力，所提出的基于 MNP 的暗场计数方法具有成本低和显著的转化潜力。
