Chiromagnetic nanoparticles and gels
Chiromagnetic nanoparticles and gels
复制标题
DOI：
10.1126/science.aao7172
复制
发表时间：
2018-01
期刊：
影响因子：
56.9
通讯作者：
Jihyeon Yeom;Uallisson S Santos;Mahshid Chekini;Minjeong Cha;A. F. de Moura;N. Kotov
中科院分区：
文献类型：
--
作者：
Jihyeon Yeom;Uallisson S Santos;Mahshid Chekini;Minjeong Cha;A. F. de Moura;N. Kotov
提高手性纳米颗粒响应联合收割机结合手性和磁性的光学纳米材料可用于磁光和作为手性催化剂。虽然手性无机纳米结构可以表现出高的圆二色性，但调节这种光学活性通常需要不可逆的化学变化。Yeom等人合成了具有l-和d-半胱氨酸表面配体的顺磁性钴氧化物（Co 3 O 4）纳米颗粒。这些配体造成了晶格的手性畸变，这种各向异性导致了更强的手性光学活性。纳米粒子凝胶在紫外线下的圆二色性可以用1.5特斯拉的磁场调制。《科学》，本期第309页手性氨基酸配体产生晶格扭曲，增强了氧化钴纳米颗粒的手性活性。手性无机纳米结构具有很高的圆二色性，但到目前为止，只有通过不可逆的化学变化才能实现对其光学活性的实时控制。场调制是一种更理想的手性光学器件的途径。我们假设，磁场调制可以实现手性纳米结构的磁跃迁偶极矩的极化旋转的大的贡献。我们发现，分散体和凝胶的顺磁性Co 3 O 4纳米粒子与手性扭曲的晶格在可见光范围内表现出手性活性，是10倍强的非顺磁性纳米粒子的可比大小。通过磁场可逆地调制纳米颗粒凝胶对紫外范围内的圆偏振光束的透明度。这些现象也观察到其他纳米级金属氧化物与晶格畸变的印迹氨基酸和其他手性配体。手性陶瓷纳米结构和凝胶的大家族可以是手性和磁性关系中新技术和知识的关键。
Boosting chiral nanoparticle responses Optical nanomaterials that combine chirality and magnetism are useful for magneto-optics and as chiral catalysts. Although chiral inorganic nanostructures can exhibit high circular dichroism, modulating this optical activity has usually required irreversible chemical changes. Yeom et al. synthesized paramagnetic cobalt oxide (Co3O4) nanoparticles with l- and d-cysteine surface ligands. These ligands created chiral distortions of the crystal lattices, and this anisotropy led to much stronger chiroptical activity. The circular dichroism in the ultraviolet of nanoparticle gels could be modulated with magnetic fields of ∼1.5 tesla. Science, this issue p. 309 Chiral amino acid ligands create lattice distortions that boost the chiroptical activity of cobalt oxide nanoparticles. Chiral inorganic nanostructures have high circular dichroism, but real-time control of their optical activity has so far been achieved only by irreversible chemical changes. Field modulation is a far more desirable path to chiroptical devices. We hypothesized that magnetic field modulation can be attained for chiral nanostructures with large contributions of the magnetic transition dipole moments to polarization rotation. We found that dispersions and gels of paramagnetic Co3O4 nanoparticles with chiral distortions of the crystal lattices exhibited chiroptical activity in the visible range that was 10 times as strong as that of nonparamagnetic nanoparticles of comparable size. Transparency of the nanoparticle gels to circularly polarized light beams in the ultraviolet range was reversibly modulated by magnetic fields. These phenomena were also observed for other nanoscale metal oxides with lattice distortions from imprinted amino acids and other chiral ligands. The large family of chiral ceramic nanostructures and gels can be pivotal for new technologies and knowledge at the nexus of chirality and magnetism.