Liebel Matz, Camargo Franco V A, Cerullo Giulio, van Hulst Niek F
ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.
Istituto di Fotonica e Nanotecnologie-CNR, Piazza L. da Vinci 32, 20133 Milano, Italy.
Nanoscale. 2022 Feb 24;14(8):3062-3068. doi: 10.1039/d1nr06837g.
Identifying, visualising and ultimately tracking dynamically moving non-fluorescent nanoparticles in the presence of non-specific scattering is a long-standing challenge across the nano- and life-sciences. In this work we demonstrate that our recently developed ultrafast holographic transient (UHT) microscope is ideally suited for meeting this challenge. We show that UHT microscopy allows reliably distinguishing off-resonant, dielectric, from resonant, metallic, nanoparticles, based on the phototransient signal: a pre-requisite for single-particle tracking in scattering environments. We then demonstrate the capability of UHT microscopy to holographically localize in 3D single particles over large volumes of view. Ultimately, we combine the two concepts to simultaneously track several tens of freely diffusing gold nanoparticles, within a 110 × 110 × 110 μm volume of view at an integration time of 10 ms per frame, while simultaneously recording their phototransient signals. The combined experimental concepts outlined and validated in this work lay the foundation for background-free 3D single-particle tracking applications or spectroscopy in scattering environments and are immediately applicable to systems as diverse as live cells and tissues or supported heterogeneous catalysts.
在存在非特异性散射的情况下，识别、可视化并最终追踪动态移动的非荧光纳米颗粒，是纳米科学和生命科学领域长期以来面临的一项挑战。在这项工作中，我们证明了我们最近开发的超快全息瞬态（UHT）显微镜非常适合应对这一挑战。我们表明，基于光瞬态信号，UHT显微镜能够可靠地区分非共振的介电纳米颗粒和共振的金属纳米颗粒：这是在散射环境中进行单颗粒追踪的先决条件。然后，我们展示了UHT显微镜在大视野体积内对单个颗粒进行三维全息定位的能力。最终，我们将这两个概念结合起来，在每帧10毫秒的积分时间内，在110×110×110μm的视野体积内同时追踪数十个自由扩散的金纳米颗粒，同时记录它们的光瞬态信号。这项工作中概述并验证的组合实验概念，为散射环境中的无背景三维单颗粒追踪应用或光谱学奠定了基础，并可立即应用于诸如活细胞和组织或负载型多相催化剂等多种系统。
