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Abstract：
The microbial hybrid system modified by magnetic nanomaterials can enhance the interfacial electron transfer and energy conversion under the stimulation of a magnetic field. However, the bioelectrocatalytic performance of a hybrid system still needs to be improved, and the mechanism of magnetic field-induced bioelectrocatalytic enhancements is still unclear. In this work, γ-Fe2O3 magnetic nanoparticles were coated on a Shewanella putrefaciens CN32 cell surface and followed by placing in an electromagnetic field. The results showed that the electromagnetic field can greatly boost the extracellular electron transfer, and the oxidation peak current of CN32@γ-Fe2O3 increased to 2.24 times under an electromagnetic field. The enhancement mechanism is mainly due to the fact that the surface modified microorganism provides an elevated contact area for the high microbial catalytic activity of the outer cell membrane\'s cytochrome, while the magnetic nanoparticles provide a networked interface between the cytoplasm and the outer membrane for boosting the fast multidimensional electron transport path in the magnetic field. This work sheds fresh scientific light on the rational design of magnetic-field-coupled electroactive microorganisms and the fundamentals of an optimal interfacial structure for a fast electron transfer process toward an efficient bioenergy conversion.
摘要：
磁性纳米材料修饰的微生物混杂体系在磁场的刺激下可以增强界面电子转移和能量转化。然而,混合系统的生物电催化性能仍有待提高，磁场诱导的生物电催化增强机制尚不清楚。在这项工作中,将γ-Fe2O3磁性纳米颗粒涂覆在希瓦氏菌CN32细胞表面上，然后放置在电磁场中。结果表明,电磁场能极大地促进细胞外电子传递,在电磁场作用下，CN32@γ-Fe2O3的氧化峰电流增加到2.24倍。其增强机制主要是由于表面修饰的微生物为细胞外膜细胞色素的高微生物催化活性提供了升高的接触面积,而磁性纳米颗粒在细胞质和外膜之间提供了一个网络接口，用于增强磁场中的快速多维电子传输路径。这项工作为磁场耦合的电活性微生物的合理设计以及用于快速电子转移过程的最佳界面结构的基本原理提供了新的科学思路。高效的生物能量转换。
