Hu Bo, Wang Ning, Han Lu, Chen Ming-Li, Wang Jian-Hua
Research Center for Analytical Sciences, College of Sciences, Box 332, Northeastern University, Shenyang 110819 (P.R. China); Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110122 (P.R. China).
Chemistry. 2015 Apr 20;21(17):6582-9. doi: 10.1002/chem.201405960. Epub 2015 Mar 9.
A novel antimicrobial nanohybrid based on near-infrared (NIR) photothermal conversion is designed for bacteria capture, separation, and sterilization (killing). Positively charged magnetic reduced graphene oxide with modification by polyethylenimine (rGO-Fe3 O4 -PEI) is prepared and then loaded with core-shell-shell Au-Ag-Au nanorods to construct the nanohybrid rGO-Fe3 O4 -Au-Ag-Au. NIR laser irradiation melts the outer Au shell and exposes the inner Ag shell, which facilitates controlled release of the silver shell. The nanohybrids combine physical photothermal sterilization as a result of the outer Au shell with the antibacterial effect of the inner Ag shell. In addition, the nanohybrid exhibits high heat conductivity because of the rGO and rapid magnetic-separation capability that is attributable to Fe3 O4 . The nanohybrid provides a significant improvement of bactericidal efficiency with respect to bare Au-Ag-Au nanorods and facilitates the isolation of bacteria from sample matrixes. A concentration of 25 μg mL(-1) of nanohybrid causes 100 % capture and separation of Escherichia coli O157:H7 (1×10(8) cfu mL(-1) ) from an aqueous medium in 10 min. In addition, it causes a 22 °C temperature rise for the surrounding solution under NIR irradiation (785 nm, 50 mW cm(-2) ) for 10 min. With magnetic separation, 30 μg mL(-1) of nanohybrid results in a 100 % killing rate for E. coli O157:H7 cells. The facile bacteria separation and photothermal sterilization is potentially feasible for environmental and/or clinical treatment.
一种基于近红外（NIR）光热转换的新型抗菌纳米杂化物被设计用于细菌捕获、分离和杀菌。制备了经聚乙烯亚胺修饰的带正电荷的磁性还原氧化石墨烯（rGO-Fe3O4-PEI），然后负载核壳壳结构的金-银-金纳米棒，构建纳米杂化物rGO-Fe3O4-Au-Ag-Au。近红外激光照射使外层金壳熔化，暴露出内层银壳，这有助于银壳的可控释放。该纳米杂化物将外层金壳的物理光热杀菌与内层银壳的抗菌作用结合起来。此外，由于rGO，纳米杂化物表现出高导热性，并且由于Fe3O4具有快速磁分离能力。相对于裸露的金-银-金纳米棒，该纳米杂化物显著提高了杀菌效率，并有助于从样品基质中分离细菌。25μg mL(-1)浓度的纳米杂化物在10分钟内可从水性介质中100%捕获和分离大肠杆菌O157:H7（1×10(8) cfu mL(-1)）。此外，在近红外照射（785nm，50 mW cm(-2)）10分钟的情况下，它会使周围溶液温度升高22°C。通过磁分离，30μg mL(-1)的纳米杂化物对大肠杆菌O157:H7细胞的杀灭率为100%。这种简便的细菌分离和光热杀菌在环境和/或临床治疗中具有潜在的可行性。
