Objective-first sorting and time resolved diamond magnetic microscopy of superparamagnetic nanoparticles

非技术性摘要：近年来，由于在生物医学成像和纳米技术中的潜在应用，磁性纳米粒子的研究已经看到了一系列的活动。然而，目前缺乏用于单个纳米颗粒的定量磁性测量的工具。本研究的目标是开发高通量，高时空分辨率表征单个磁性纳米颗粒的新策略。使用基于合成金刚石芯片的新型磁性显微镜同时表征数千个单个纳米颗粒的磁性。与现有技术不同，金刚石芯片平台在室温下工作，并提供高通量（每10分钟超过1000个单个颗粒）。该项目旨在将每个纳米颗粒的磁性测量与其组成，大小，形状和结构相关联。最后，拟议的研究还旨在教育和培训不同群体的高中生，本科生和研究生，包括代表性不足的群体。技术摘要。本研究的目标是开发替代策略，用于单个磁性纳米颗粒的高灵敏度，并行表征。该研究项目旨在研究直径为15-25 nm的超顺磁性氧化铁纳米颗粒的磁动力学，目的是提高其在纳米科学应用中的适用性。使用基于掺杂在金刚石芯片表面附近的色心的磁性显微镜同时表征数千个单独的纳米颗粒的磁性。相关的透射电子显微镜和许多单独的纳米粒子的磁性图像被用来阐明纳米粒子的大小，形状，磁化弛豫和磁滞曲线特性之间的关系。该研究项目的第二个目的是研究尺寸范围（2-10 nm）的小过渡金属磁性纳米颗粒的组成，形态和磁动力学的相关性，并建立对尺寸，表面结构和颗粒间偶极相互作用对其磁性能影响的基本理解。对于一个400 nm x 400 nm的像素，在1秒积分时间内10 nT的目标磁灵敏度足以表征直径小至2 nm的颗粒。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical abstract: Magnetic nanoparticle research has seen a flurry of activity in recent years, owing to potential applications in biomedical imaging and nanotechnology. However there is presently a lack of tools for quantitative magnetic measurements of individual nanoparticles. The goal of this research is to develop new strategies for high throughput, high spatio-temporal resolution characterization of individual magnetic nanoparticles. The magnetic properties of thousands of individual nanoparticles are simultaneously characterized using a new type of magnetic microscope based on synthetic diamond chips. Unlike existing techniques, the diamond-chip platform works at room temperature and offers high throughput (greater than 1000 individual particles per 10 min). The project aims to correlate magnetic measurements for each individual nanoparticle with its composition, size, shape, and structure. Finally, the proposed research also aims to educate and train diverse groups of high school students, undergraduates, and graduate students, including under-represented groups. Technical abstract. The goal of this research is to develop alternative strategies for high-sensitivity, parallel characterization of individual magnetic nanoparticles. The research project aims to study the magnetic dynamics of superparamagnetic iron oxide nanoparticles with 15-25 nm diameter, with a goal of improving their applicability in nanoscience applications. The magnetic properties of thousands of individual nanoparticles are simultaneously characterized using a magnetic microscope based on color centers doped near the surface of a diamond chip. Correlative transmission electron microscopy and magnetic images of numerous individual nanoparticles is used to elucidate the relationship between nanoparticle size, shape, magnetization relaxation, and hysteresis curve properties. A second aim of this research project is to study the correlation of composition, morphology, and magnetic dynamics of small transition metallic magnetic nanoparticles with a size range (2-10 nm) and establish a fundamental understanding of the effect of size, surface structure, and inter-particle dipolar interactions on their magnetic properties. The target magnetic sensitivity of 10 nT in 1 second integration time for a 400 nm x 400 nm pixel is sufficient to characterize particles down to 2 nm in diameter.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.