中文摘要：本文介绍了一种便携式核磁共振生物传感器及其在高灵敏快速检测复杂基质食源性致病菌大肠杆菌O157:H7中的应用，该传感器使用被具有抗体功能的聚合物包裹的磁性纳米粒子作细菌生物标志物，可加速核磁共振信号衰减。该传感器在0.47特斯拉磁场强度下工作，并且由一种高功率脉冲射频发射机和超低噪声检测电路组成，能够在0.1μm范围内检测到微弱的核磁共振信号。本文应用该传感器检测饮用水和牛奶样本中大肠杆菌O157:H7，结果显示，加入过滤步骤后，该传感器能够在一分钟内，检测到饮用水和牛奶样本中低至76 CFU/mL和92CFU/mL的大肠杆菌O157:H7。该传感器在食物基质中检测食源性致病菌是应用上的一种创新，通过改变抗体可以扩展到其他微生物或病毒的特异性检测中，该传感器在生物防御和医疗诊断的快速检测方面也具有一定的应用潜力。
外文摘要：Background: Nuclear magnetic resonance (NMR) technique is a powerful analytical tool in determining the presence of bacterial contaminants in complex biological samples. In this paper, a portable NMR-based (pNMR) biosensor and assay to detect the foodborne bacteria Escherichia coli O157: H7 is reported. It uses antibody-functionalized polymer-coated magnetic nanoparticles as proximity biomarker of the bacteria which accelerates NMR resonance signal decay. Results: The pNMR biosensor operates at 0.47 Tesla of magnetic strength and consists of a high-power pulsed RF transmitter and an ultra-low noise sensing circuitry capable of detecting weak NMR signal at 0.1 mu V. The pNMR biosensor assay and sensing mechanism is used in detecting E. coli O157: H7 bacteria in drinking water and milk samples. Experimental results demonstrate that by adding a filtration step in the assay, the pNMR biosensor is able to detect E. coli O157: H7 as low as 76 CFU/mL in water samples and as low as 92 CFU/mL in milk samples in about one min. Conclusion: The pNMR biosensor assay and sensing system is innovative for foodborne bacterial detection in food matrices. The lowest detection level for E. coli O157: H7 in water and milk samples is essentially 101 CFU/mL. Although the linear range of detection is only from 101 to 104 CFU/mL, the wider detection range spans from 101 CFU/mL to 107 CFU/mL. Existing pNMR biosensors have detection limits at 103-104 CFU/mL only. The detection technique can be extended to other microbial or viral organisms by merely changing the specificity of the antibodies. Besides food safety, the pNMR biosensor described in this paper has potential to be applied as a rapid detection device in biodefense and healthcare diagnostic applications.
外文关键词：Biosensors, Nuclear magnetic resonance, Nanotechnology, Magnetic nanoparticles, Magnetic separation
作者：Luo, Yilun; Alocilja, Evangelyn C.
作者单位：Michigan State Univ, Dept Biosyst & Agr Engn, E Lansing, MI 48824 USA.
期刊名称：JOURNAL OF BIOLOGICAL ENGINEERING
期刊影响因子：3.0
出版年份：2017
出版刊次：3
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