Tailored Magnetic Nanoparticles for Direct and Sensitive Detection of Biomolecules in Biological Samples
Tailored Magnetic Nanoparticles for Direct and Sensitive Detection of Biomolecules in Biological Samples
复制标题
DOI：
10.1021/nl8022498
复制
发表时间：
2008-10-01
期刊：
影响因子：
10.8
通讯作者：
Johansson, Christer
中科院分区：
文献类型：
--
作者：
Fornara, Andrea;Johansson, Petter;Johansson, Christer
我们开发了具有定制磁性的纳米颗粒，可一步直接、灵敏地检测生物样品中的生物分子。通过热水解获得的热封闭纳米粒子，用特定配体功能化，与样品溶液混合，并且由于表面结合而产生的磁弛豫变化用于检测生物分子的存在。这种结合显着增加了纳米颗粒的流体动力学体积，从而改变了它们的布朗弛豫频率，该频率由专门开发的交流电感受器测量。该系统在受感染牛的血清样本中测试了布鲁氏菌抗体的存在，布鲁氏菌抗体是一种危险的病原体，会引起布鲁氏菌病，对人类和动物都有严重影响，纳米颗粒的表面被来自流产布鲁氏菌的脂多糖（LPS）功能化。通过交变磁场中磁化率的变化测量，由于抗体的结合，LPS 功能化颗粒的流体动力学体积增加了 25-35%。该方法灵敏度高，无需任何预处理，生物样品中抗体的检出限可达0.05μg.mL(-1)。这种基于磁性的检测非常灵敏、经济高效且用途广泛，可以直接指示动物是否受到感染，使其适合即时护理应用。定制的磁性纳米颗粒的功能化可以进行修改，以适应各种应用的多种均相测定。
We developed nanoparticles with tailored magnetic properties for direct and sensitive detection of biomolecules in biological samples in a single step. Thermally blocked nanoparticles obtained by thermal hydrolysis, functionalized with specific ligands, are mixed with sample solutions, and the variation of the magnetic relaxation due to surface binding is used to detect the presence of biomolecules. The binding significantly increases the hydrodynamic volume of nanoparticles, thus changing their Brownian relaxation frequency which is measured by a specifically developed AC susceptometer, The system was tested for the presence of Brucelia antibodies, a dangerous pathogen causing brucellosis with severe effects both on humans and animals, in serum samples from infected cows and the surface of the nanoparticles was functionalized with lipopolysaccarides (LPS) from Brucella abortus. The hydrodynamic volume of LPS-functionalized particles increased by 25-35% as a result of the binding of the antibodies, measured by changes in the susceptibility in an alternating magnetic field. The method has shown high sensitivity, with detection limit of 0.05 mu g.mL(-1) of antibody in the biological samples without any pretreatment. This magnetic-based assay is very sensitive, cost-efficient, and versatile, giving a direct indication whether the animal is infected or not, making it suitable for point-of-care applications. The functionalization of tailored magnetic nanoparticles can be modified to suit numerous homogeneous assays for a wide range of applications.