Nanomagnetic Arrays Formed with the Biomineralization Protein Mms6
Nanomagnetic Arrays Formed with the Biomineralization Protein Mms6
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DOI：
10.4028/www.scientific.net/jnanor.17.127
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发表时间：
2012-02
影响因子：
1.7
通讯作者：
J. M. Galloway;J. P. Bramble;Andrea E. Rawlings;G. Burnell;S. Evans;Sarah S. Staniland
中科院分区：
文献类型：
--
作者：
J. M. Galloway;J. P. Bramble;Andrea E. Rawlings;G. Burnell;S. Evans;Sarah S. Staniland
许多现代技术，如高密度数据存储，需要单分散的磁性纳米颗粒（MNP），其具有一致的磁性行为，特别是固定在图案化表面上。目前用于合成均匀MNP的方法需要高温和苛刻的化学品，这是不环保的。而且，颗粒制造昂贵，并且使用常规光刻方法图案化昂贵。磁性细菌能够在体内合成一致的Mnps，使用磁小体囊泡内的生物矿化蛋白来控制颗粒大小和形状并制造单域Mnps。Mms 6是一种生物矿化蛋白，能够在体外模板立方八面体MNP形成。据认为，N-末端有助于将蛋白质整合到磁小体膜中，并且C-末端在成核和/或MNP生长期间与磁铁矿相互作用。通过选择性地将Mms 6经由N-端附着到图案化的自组装单层，原位模板化均匀的磁铁矿Mnps图案。这也需要仔细选择用于矿化图案化MMS 6的矿化溶液。在此，我们评估了一些低温（室温至< 100°C）磁铁矿形成方法以在固定化的Mms 6上产生单分散的磁铁矿MnP。发现室温共沉淀（RTCP）是不合适的，因为磁铁矿不会在固定化的Mms 6上形成，但似乎随着碱的加入而快速形成。发现氢氧化亚铁（POFH）的部分氧化能够在固定化的Mms 6上形成一致的磁铁矿Mnps，因为反应物在几小时（在80°C下）或几天（室温）内逐渐成熟以形成磁铁矿。通过仔细控制所用碱的类型、反应物的比例以及POFH矿化反应的温度和持续时间，该系统被优化以在固定化Mms 6上产生一致的Mnps（340 ± 54 Nm，矫顽力109 Oe），在抗生物污染背景下几乎没有任何矿化。MNPS是铁磁性的，并且在MFM测量中似乎是跨多个粒子的交换耦合。该方法在相对温和的条件下对精确磁铁矿矿化的特异性可通过使用其它生物矿化蛋白质或肽而适用于多种生物模板材料的纳米级图案化。这将允许为未来的设备制造更便宜、更环保的部件。
Many Modern Technologies, such as High Density Data Storage, Require Monodispersed Magnetic Nanoparticles (MNPs), which Have a Consistent Magnetic Behavior, Specifically Immobilized onto a Patterned Surface. Current Methods for Synthesizing Uniform Mnps Require High Temperatures and Harsh Chemicals, which Is Not Environmentally Friendly. Also, the Particles Are Expensive to Make and Expensive to Pattern Using Conventional Lithography Methods. Magnetic Bacteria Are Able to Synthesize Consistent Mnps in Vivo Using Biomineralization Proteins inside Magnetosome Vesicles to Control Particle Size and Shape and Make Single Domain Mnps. Mms6 Is a Biomineralization Protein that Is Able to Template Cubo-Octahedral MNP Formation in Vitro. it Is Thought the N-Terminus Helps Integrate the Protein into the Magnetosome Membrane, and the C-Terminus Interacts with Magnetite during Nucleation and/or MNP Growth. by Selectively Attaching Mms6 to a Patterned Self Assembled Monolayer via the N-Terminus, Patterns of Uniform Magnetite Mnps Are Templated in Situ. this Also Requires Careful Selection of the Mineralization Solution Used to Mineralize the Patterned Mms6. here we Evaluate some Low Temperature (room Temperature to < 100°C) Methods of Magnetite Formation to Produce Monodispersed Magnetite Mnps onto Immobilized Mms6. Room Temperature Co-Precipitation (RTCP) Was Found to Be Unsuitable, as the Magnetite Does Not Form on the Immobilized Mms6, but Appears to Form Rapidly as Base Is Added. Partial Oxidation of Ferrous Hydroxide (POFH) Was Found to Be Able to Form Consistent Magnetite Mnps on the Immobilized Mms6, as the Reactants Gradually Mature to Form Magnetite over a few Hours (at 80°C) or a few Days (room Temperature). by Carefully Controlling the Type of Base Used, the Ratio of the Reactants and the Temperature and Duration of the POFH Mineralization Reaction, this System Was Optimized to Produce Consistent Mnps (340 ± 54 Nm, Coercivity 109 Oe) on the Immobilized Mms6, with Scarcely any Mineralization on the Anti-Biofouling Background. the Mnps Are Ferrimagnetic, and Appear to Be Exchange Coupled across Multiple Particles in MFM Measurements. the Specificity of this Method towards Precise Magnetite Mineralization under Relatively Mild Conditions May Be Adapted to Nanoscale Patterning of Multiple Biotemplated Materials, by Using other Biomineralization Proteins or Peptides. this Would Allow the Fabrication of Cheaper, More Environmentally Friendly Components for Devices of the Future.