Probing Contrast Mechanisms of Super-resolution Atomic Force Microscopy for Imaging Multifunctional Self-assembled Monolayers

在化学系化学测量和成像计划的支持下，加州大学默塞德分校的叶涛教授和阿什莉·马蒂尼教授正在结合实验和计算方法，研究分子如何在原子水平上相互作用，以及这种相互作用如何影响成像工具-原子力显微镜的分辨率。他们希望他们的发现能够提高在实际操作条件下成像复杂的、技术相关的表面的能力，例如生物传感器和设备。鉴于生物传感器和设备在可穿戴技术、个性化医疗和国家安全中的重要性，通过该项目取得的进展可能会带来长期的经济和社会效益。该项目的研究目标得到了教育/外展目标的补充，这些目标利用了加州大学默塞德分校多样化的学生群体。叶教授和马蒂尼教授计划积极从代表性不足的群体中招聘和培养有才华的研究生和本科生。研究团队还通过各种机制与大学前的观众进行接触。该研究项目的一个关键目标是了解原子力显微镜(AFM)尖端(即尖端)上的少量原子与表面少量原子之间的相互作用力；这些相互作用最终决定了原位原子力显微镜的亚纳米级对比度。叶教授和马蒂尼教授正在通过将纳米级化学图案的非接触成像与经过化学修饰的AFM尖端和最先进的AFM成像的分子动力学模拟相结合，阐明导致亚纳米级对比度的化学力的本质。此外，该团队正在应用这些知识来获得DNA功能化自组装单分子膜分子组成的更具重复性的超分辨率图谱，这些单分子膜已广泛用于电化学DNA传感器。所提出的新的实验和计算方法正在填补亚纳米分辨率原子力显微镜图像对比度机制方面的关键知识空白，使其成为一种更具重复性和更广泛适用的表面化学成像工具。新的进展可能适用于各种表面，包括基于自组装的单层生物传感器、微阵列和支撑的脂类双层，并可能影响从生物技术到生命科学的领域。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。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professors Tao Ye and Ashlie Martini at University of California, Merced, are combining experimental and computational approaches to study how molecules interact at the atomic level and how this interaction affects the resolution of an imaging tool -atomic force microscope. They hope their findings could improve the ability to image complex, technologically relevant surfaces such as biosensors and devices under practical operating conditions. Given the importance of biosensors and devices in wearable technologies, personalized medicine and national security, the advances made through this project could potentially offer long-term economic and societal benefits. The research goals of the project are complemented by education/outreach objectives that leverage the diverse student population at UC Merced. Professors Ye and Martini plan to actively recruit and train talented graduate and undergraduate students from underrepresented groups. The research team is also engaging with pre-college audiences through a variety of mechanisms. A key goal of the research project is to understand the interaction forces between a small number of atoms at the very end of the atomic force microscope (AFM) tip, i.e., the tip apex, and a small number of atoms on the surface; these interactions ultimately determine the subnanometer scale contrast of in situ atomic force microscopy. Professors Ye and Martini are elucidating the nature of the chemical forces responsible for subnanometer-scale contrast by combining non-contact imaging of nanoscale chemical patterns with a chemically modified AFM tip apex and state-of-the-art molecular dynamics simulations of AFM imaging. Moreover, the team is applying the knowledge to obtain more reproducible super-resolution mapping of the molecular components of DNA-functionalized self-assembled monolayers that have been widely used in electrochemical DNA sensors. The proposed new experimental and computational approaches are filling a critical knowledge gap in the image contrast mechanisms of subnanometer resolution AFM and allow it to become a more reproducible and broadly applicable surface chemical imaging tool. The new advances may be applicable to a variety of surfaces, including self-assembled monolayer-based biosensors, microarrays, and supported lipid bilayers, and can impact fields from biotechnology to life sciences.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.