The fast and efficient elimination of pathogenic bacteria from water, food or biological samples such as blood remains a challenging task. Magnetic isolation of bacteria from complex media holds particular promise for water disinfection and other biotechnological applications employing bacteria. When it comes to infectious diseases such as urinary tract infections, the selective removal of the pathogenic species in complex media such as human serum is also of importance. This issue can only be accomplished by adding pathogen specific targeting sites onto the magnetic nanostructures. In this work, we investigate the potential of 2-nitrodopamine modified magnetic particles anchored on reduced graphene oxide (rGO) nanocomposites for rapid capture and efficient elimination of E. coli associated with urinary tract infections (UTIs) from water and serum samples. An optimized magnetic nanocarrier achieves a 99.9% capture efficiency even at E. coli concentrations of 1 × 10¹ cfu mL⁻¹ in 30 min. In addition, functionalization of the nanostructures with poly(ethylene glycol) modified pyrene units and anti-fimbrial E. coli antibodies allowed specific elimination of E. coli UTI89 from serum samples. Irradiation of the E. coli loaded nanocomposite with a near-infrared laser results in the total ablation of the captured pathogens. This method can be flexibly modified for any other pathogenic bacteria, depending on the antibodies used, and might be an interesting alternative material for a magnetic-based body fluid purification approach.

中文翻译：

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使用抗纤维修饰的磁性还原氧化石墨烯纳米加热器选择性分离和根除与尿路感染相关的大肠杆菌

从水，食物或血液等生物样本中快速有效地清除病原细菌仍然是一项艰巨的任务。细菌与复杂介质的磁隔离在水消毒和其他利用细菌的生物技术应用中具有特殊的前景。当涉及诸如尿路感染的传染性疾病时，在诸如人血清之类的复杂介质中选择性去除病原体也很重要。这个问题只能通过将病原体特异性靶向位点添加到磁性纳米结构上来解决。在这项工作中，我们研究了2-硝基多巴胺修饰的磁性颗粒锚定在还原的氧化石墨烯（rGO）纳米复合材料上的潜力，以快速捕获和有效消除大肠杆菌。与水和血清样本中的尿路感染（UTI）相关。即使在30分钟内大肠杆菌浓度为1×10 ¹ cfu mL ^{-1的情况下}，经过优化的磁性纳米载体也可实现99.9％的捕获效率。另外，用聚（乙二醇）修饰的pyr单元和抗纤维化大肠杆菌抗体对纳米结构进行功能化可以从血清样品中特异性消除大肠杆菌UTI89。大肠杆菌的辐照载有近红外激光的纳米复合材料可完全消灭捕获的病原体。根据所使用的抗体，可以针对任何其他病原细菌灵活修改此方法，对于基于磁性的体液纯化方法来说，该方法可能是一种令人感兴趣的替代材料。