Guangdong Engineering and Technology Research Center for Advanced Nanomaterials, School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China.
Department of Chemical Engineering, Shaanxi Key Laboratory of Energy Chemical Process Intensification, Institute of Polymer Science in Chemical Engineering, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
Nano Lett. 2022 Sep 14;22(17):7136-7143. doi: 10.1021/acs.nanolett.2c02269. Epub 2022 Aug 26.
Single-beam super-resolution microscopy, also known as superlinear microscopy, exploits the nonlinear response of fluorescent probes in confocal microscopy. The technique requires no complex purpose-built system, light field modulation, or beam shaping. Here, we present a strategy to enhance this technique's spatial resolution by modulating excitation intensity during image acquisition. This modulation induces dynamic optical nonlinearity in upconversion nanoparticles (UCNPs), resulting in variations of nonlinear fluorescence response in the obtained images. The higher orders of fluorescence response can be extracted with a proposed weighted finite difference imaging algorithm from raw fluorescence images to generate an image with higher resolution than superlinear microscopy images. We apply this approach to resolve single nanoparticles in a large area, improving the resolution to 132 nm. This work suggests a new scope for the development of dynamic nonlinear fluorescent probes in super-resolution nanoscopy.
单束超分辨率显微镜，也称为超线性显微镜，利用共焦显微镜中荧光探针的非线性响应。该技术不需要复杂的专用系统、光场调制或光束成形。在这里，我们提出了一种通过在图像采集过程中调制激发强度来增强该技术空间分辨率的策略。这种调制会在上转换纳米粒子（UCNP）中引起动态光学非线性，从而导致获得的图像中非线性荧光响应的变化。通过从原始荧光图像中提取的加权有限差分成像算法，可以提取更高阶的荧光响应，从而生成比超线性显微镜图像具有更高分辨率的图像。我们将此方法应用于在大面积上解析单个纳米粒子，将分辨率提高到 132nm。这项工作为超分辨率纳米显微镜中动态非线性荧光探针的发展提供了新的前景。
