CAREER: Multiscale Simulations of Iron Oxide Nanoparticle-Protein Electron Transfer

金属氧化物纳米颗粒与金属还原细菌结合可以产生反应过程，应用于污染土壤和水的生物修复。挑战是提高目前这些反应的低效率，这关键取决于纳米颗粒如何与外膜蛋白相互作用。这个职业项目将研究氧化铁纳米粒子-蛋白质电子转移反应，目的是开发更有效的环境应用技术。从这个项目中获得的知识也是非常可取的，并适用于生物能源、生物兼容材料和生物传感器的技术开发。这项研究将对化学和生物医学工程、材料科学、化学和生物学等多个学科的科学探索产生重大影响。通过将研究和教育相结合的有针对性的努力，该项目将提供前沿研究机会，以促进本科生和研究生，特别是来自代表性不足的社区的STEM教育，并将为K-12教师和学生以及普通公众提供拓宽STEM经验的教育活动。该项目的总体研究目标是阐明氧化铁纳米颗粒-蛋白质电子转移和氧化还原的机理，这是利用纳米氧化铁-异化金属还原细菌耦合的环境应用所迫切需要的。由于缺乏合适的纳米生物系统的模拟方法和参数，这方面的协同理论研究很少。为了应对涉及蛋白质构象变化、化学反应和电子转移的多尺度计算挑战，该项目将包括量子、原子和分子水平的多尺度模拟，并辅之以循环伏安实验、线性和非线性振动光谱以及虚拟可视化。将在理论和量子计算的基础上开发电子转移和纳米粒子-蛋白质相互作用和反应的模拟参数。非生物-生物界面电子转移的潜在机制以及纳米粒子-蛋白质在多尺度上的物理相互作用和化学反应的相关分子细节将被研究。研究了脂多糖、磷脂、外膜和纳米粒子的性质对蛋白质界面行为和界面电子转移的影响。纳米粒子性质、蛋白质二级结构、纳米粒子表面取向和电子转移性质的模拟结果将通过实验测量得到验证。模拟还将有助于解释实验循环伏安信号以及线性和非线性振动光谱。这项工作将为有关纳米生物界面现象的物理和化学提供有价值的见解，并将促进高效生物纳米技术的发展。该项目的教育目标是通过提供世界级的工程教育和研究机会，在大学和K-12阶段加强对未被充分代表的少数民族学生的STEM教育。该项目的研究活动和成果将纳入新的课程和学生研究机会，以招收和留住STEM领域的少数族裔学生。该项目还将提供STEM教师工作坊，向高中生介绍研究项目，并促进公众的科学素养。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Metal oxide nanoparticles coupled with metal-reducing bacteria can generate reaction processes for applications in bio-remediation of contaminated soil and water. The challenge is to increase the currently low efficiency of these reactions, which critically depend on how nanoparticles interact with the outer membrane proteins. This CAREER project will investigate iron oxide nanoparticle-protein electron transfer reaction for the purpose of developing more efficient technologies for environmental applications. The knowledge obtained from this project is also highly desirable and applicable to technology development in bioenergy, biocompatible materials and biosensors. This research will greatly impact the scientific exploration in many disciplines, including chemical and biomedical engineering, material science, chemistry and biology. Through targeted efforts that integrate research and education, this project will provide cutting-edge research opportunities to promote STEM education for undergraduate and graduate students, particularly those from underrepresented communities, and will offer education activities to broaden STEM experiences for K-12 teachers and students as well as for the general public.The overall research goal of this project is to elucidate the mechanism of iron oxide nanoparticle-protein electron transfer and redox, which is greatly needed for environmental applications utilizing coupled iron oxide nanoparticle-dissimilatory metal-reducing bacteria. Due to the lack of a proper simulation approach and parameters for nano-bio systems, there are few synergistic theoretical studies in this area. To tackle computational challenges at multiscale levels, involving protein conformation changes, chemical reactions and electron transfer, this project will incorporate multiscale simulations at the quantum, atomistic and molecular levels, complemented by experiments of cyclic voltammogram and linear and nonlinear vibrational spectroscopies as well as virtual visualization. Simulation parameters of electron transfer and nanoparticle-protein interactions and reactions will be developed based on theory and quantum computations. The underlying mechanism of the abiotic-biotic interfacial electron transfer and the associated molecular details of nanoparticle-protein's physical interactions and chemical reactions at multiscales will be investigated. The effects of lipopolysaccharide, phospholipids, outer membrane and properties of nanoparticles on protein interfacial behavior and the interfacial electron transfer will be studied. The simulation results of nanoparticle properties, protein secondary structure, orientation on nanoparticle surfaces and electron transfer properties will be verified by experimental measurements. Simulations will also help interpret experimental cyclic voltammogram signals and linear and nonlinear vibrational spectra. This work will provide valuable insights into physics and chemistry regarding nano-bio interfacial phenomena and will promote the development of efficient bio-nano technologies. The educational goal of this project is to enhance STEM education for underrepresented minority students at university and K-12 levels by providing world-class engineering education and research opportunities. The research activities and results of this project will be incorporated into new courses and student research opportunities to recruit and retain minority students in STEM fields. This project will also offer STEM teacher workshops, introduce high school students to research projects, and promote the scientific literacy of the general public.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.