基于液滴微透镜的光学探测与纳米成像

Optical detection and imaging of nano-objects such as nanoparticles, bacterial viruses, biomolecules and subcellular structures is crucial for biosensing, medical diagnosis and single-molecule study. However, due to the diffraction limit of light, it is challenging for conventional optical methods to detect and image objects smaller than 100 nm in size. Recently, microlens-based techniques such as plasmonic superlenses, solid immersion microlenses, dielectric microsphere lenses, have been developed to overcome the diffraction limit. However, the existing microlenses are fabricated by inorganic solid materials such as metals or semiconductors, which are incompatible with biological tissues and living cells. Inspired by a natural phenomenon that droplets on the surface of a leaf can amplify the veins, we propose to design and prepare a biocompatible droplet microlens for optical detection and imaging of sub-100-nm objects. Furthermore, we plan to use optical tweezers to manipulate the droplet microlens and to investigate the high-precision detection and super-resolution imaging inside living cells.

对超微颗粒、细菌病毒、生物分子、亚细胞结构等纳米物体实施光学探测和显微成像在生物传感、医学诊断、单分子研究等交叉学科领域具有重要意义。然而，由于光学衍射极限的存在，限制了光与纳米物体的相互作用，导致传统光学方法难以探测和观察尺寸小于一百纳米的物体。最近发展的近场微透镜技术如等离激元超透镜、固体浸没微透镜、介质微球透镜等，能够克服光的衍射极限，增强光与物质的相互作用。然而，现有的微透镜均由金属或半导体等无机固体材料制备而成，与生物组织和细胞不兼容。受大自然中叶片表面的水滴能放大叶脉这一现象的启发，本项目拟设计和制备一种生物兼容的液滴微透镜，对尺寸小于一百纳米的物体实施光学探测和成像，进一步，拟利用光镊技术操控液滴微透镜使其可以灵活移动，并探索液滴微透镜在活体细胞内部的高精度探测与超分辨成像。

微球透镜因其易集成和小型化等优点，在超分辨光学成像、生物传感等领域具有重要应用。国际上提出的微球透镜一般由固体材料构成，生物兼容性较低，且在生物环境中难以降解。本项目利用一步乳化法制备了大小可控和形状规则的液滴微透镜，并构建了活细胞内生物兼容的脂质液滴微透镜，实现了对量子点、纳米光栅、细胞骨架、线粒体、细菌病毒等的超分辨成像和信号增强，推动了液滴微透镜在生物成像与信号探测的一体化进程。在项目执行期间，发表相关学术论文9篇，其中以第一作者或通讯作者发表在Light：Science & Applications、Nano Letters、Advanced Science等学术期刊。申请中国发明专利4项，其中授权专利2项。获2022年度广东省光学学会光学科技奖（1/3）。