School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
J Phys Chem Lett. 2020 Jul 16;11(14):5785-5791. doi: 10.1021/acs.jpclett.0c01536. Epub 2020 Jul 7.
Chemical characterizations of biochemically functionalized single nanoparticles are necessary to optimize the nanoparticle surface functionality in recently advanced nanobiological applications but have not yet been fully explored because of technical difficulties. Exploiting the photoinduced force exerted on a light-illuminated nanoscale tip, nanoscale mid-infrared hyperspectral images with a 10 nm spatial resolution of a monolayer ligand-functionalized single gold nanoparticle under ambient and environmental conditions are presented. We extend our study to the diagnosis of nanoscale heterogeneous chemical contaminants which come from a particle functionalization process but are undetectable in conventional ensemble-averaged imaging technique. High sensitivity and high spatial resolution are achieved via the strongly localized tip-enhanced force at the junction between the gold-coated tip and the functionalized nanoparticle in photoinduced force microscopy, which far exceeds the capability of the conventional methods. The present study paves a new way to directly detect heterogeneous nanochemicals at the single-component level, which is necessary to evaluate nanomaterial safety in biomedical applications.
为了优化最近先进的纳米生物学应用中纳米粒子表面的功能，需要对具有生物化学功能的单颗粒进行化学特性分析，但由于技术困难，这方面的研究还没有完全展开。本研究利用光照射纳米级尖端上产生的光致力，在环境条件下展示了单层配体功能化单金纳米粒子的纳米级中红外高光谱图像，空间分辨率为 10nm。我们将研究扩展到纳米级异质化学污染物的诊断，这些污染物来自于颗粒功能化过程，但在传统的平均成像技术中是无法检测到的。通过光诱导力显微镜中在金涂层尖端和功能化纳米颗粒之间的交界处的强局域化尖端增强力，实现了高灵敏度和高空间分辨率，其能力远远超过了传统方法。本研究为在单一组分水平上直接检测异质纳米化学物质开辟了新途径，这对于评估生物医学应用中纳米材料的安全性是必要的。
