Li Jiajun, Mu Yunyun, Liu Miao, Zhang Xinping
Institute of Information Photonics Technology, Beijing University of Technology, Beijing 100124, China.
Nanomaterials (Basel). 2022 Aug 18;12(16):2843. doi: 10.3390/nano12162843.
We report the direct laser writing (DLW) of surface-enhanced Raman scattering (SERS) structures on the inner wall of a hollow fiber. Colloidal gold-silver alloy nanoparticles (Au-Ag ANPs) are firstly coated onto the inner wall of a hollow fiber. A green laser beam is focused through the outer surface of the hollow fiber to interact with colloidal Au-Ag ANPs so that they become melted and aggregated on the surface of the inner wall with strong adhesion. Such randomly distributed plasmonic nanostructures with high density and small gaps favor the SERS detection of low-concentration molecules in liquids flowing through the hollow fiber. Such a SERS device also supplies a three-dimensional microcavity for the interaction between excitation laser and the target molecules. The DLW system consists mainly of the flexible connection between the motor shaft and the hollow fiber, the program-controlled translation of the hollow fiber along its symmetric axis and rotation about the axis, as well as the mechanical design and the computer control system. This DLW technique enables high production, high stability, high reproducibility, high precision, and a high-flexibility fabrication of the hollow fiber SERS device. The resultant microcavity SERS scheme enables the high-sensitivity detection of R6G molecules in ethanol with a concentration of 10 mol/L.
我们报道了在中空纤维内壁上直接激光写入（DLW）表面增强拉曼散射（SERS）结构。首先将胶体金-银合金纳米颗粒（Au-Ag ANPs）涂覆在中空纤维的内壁上。一束绿色激光束通过中空纤维的外表面聚焦，与胶体Au-Ag ANPs相互作用，使其在内壁表面熔化并聚集，具有很强的附着力。这种随机分布的高密度和小间隙的等离子体纳米结构有利于对流过中空纤维的液体中的低浓度分子进行SERS检测。这种SERS装置还为激发激光与目标分子之间的相互作用提供了一个三维微腔。DLW系统主要由电机轴与中空纤维之间的柔性连接、中空纤维沿其对称轴的程控平移和绕轴旋转，以及机械设计和计算机控制系统组成。这种DLW技术能够实现中空纤维SERS装置的高产量、高稳定性、高再现性、高精度和高灵活性制造。所得的微腔SERS方案能够对浓度为10 mol/L的乙醇中的R6G分子进行高灵敏度检测。
