毕赤酵母-表面活性剂协同作用制备Au纳米线

在毕赤酵母-十六烷基三甲基溴化铵(CTAB)的协同作用下利用抗坏血酸(AA)还原氯金酸(HAuCl₄)制备Au纳米线, 采用SEM、TEM、HRTEM及SAED等手段对Au产物进行表征,结果表明产物为带有分支结构的Au纳米线,纳米线在分叉处的晶型是连续的,具有多晶结构的特征。研究发现,菌体-HAuCl₄的相互作用对于后续纳米线的生成过程至关重要,部分Au(Ⅲ)可吸附在菌体表面并被还原为很小的Au(0),在AA加入后纳米线的生成过程中起到了晶种的作用。菌体-HAuCl₄作用时间过长会导致菌体表面生成的Au(0)趋于稳定,不利于进一步生长为Au纳米线。菌体-表面活性剂的协同作用导致分支结构的多晶Au纳米线的生成。

Preparation of Au nanowires based on synergistic action of Pichia pastoris cells and surfactant

Au nanowires (AuNWs) were obtained by the reduction of HAuCl₄ with ascorbic acid (AA) under the synergistic action between microorganism (Pichia pastoris cells, PPCs) and hexadecyltrimethylammonium bromides (CTAB). SEM, TEM, HRTEM and SEAD were used to characterize the shape and structure feature of the Au nanoproducts. The results showed the AuNWs were hierarchically branched polycrystal and the interfaces of the branched positions were continuous in lattice. The interaction process between the microorganism and CTAB was researched and it was found that Au(0) could be formed on the PPCs surface, which acted as the seeds for the formation of AuNWs after AA addtion. Without the interaction process between the microorganism and CTAB, the Au nanoparticles instead of nanowires were acquired. Too long time adsorption between PPCs and HAuCl₄ led to stable Au(0) on the microorganism surface, which was also unfavorable for the subsequent growth of AuNWs. The synergistic action between microorganism and CTAB resulted in the formation of AuNWs with hierarchically branched polycrystalline structure.