研究目的
To fabricate noble metal nanostructures with large SERS enhancement factor (EF) onto optical fiber surfaces for liquid-phase in situ and remote SERS detections.
研究成果
Au nanorod clusters were successfully fabricated on optical fiber facets by a simple and low-cost laser-induced evaporation self-assembly method. The probes demonstrated high SERS detection sensitivity and excellent detection reproducibility, making them suitable for liquid-phase in situ detection fields such as food safety, environmental science, and biosensing.
研究不足
The method requires optimization of the number of dipping-pulling cycles, the power of the evaporation-inducing laser, the pulling speed of the dip-coater, and the residence time in air to achieve the best performance. Excessive heat from the photothermal effect of the large clusters may cause the deformation of Au nanorods.
1：Experimental Design and Method Selection
A laboratory-developed laser-induced evaporation self-assembly method was used to prepare the nanoparticle cluster patterned optical fiber SERS probes. The method involves multiple automatic dipping-pulling processes performed using a programmable dip-coater.
2：Sample Selection and Data Sources
Au nanorod colloid was purchased from NanoSeedz (Hong Kong). Multi-mode quartz optical fibers were purchased from Thorlabs. Milli-Q deionized water was used in all the experiments.
3：List of Experimental Equipment and Materials
A 15-cm long multimode quartz optical fiber (200/220 μm, NA=0.22), a 785-nm wavelength semiconductor laser, a fiber cleaver, a dip-coater controlled by a computer program, a portable Raman spectrometer (QE-Pro, Ocean Optics, USA), and a high-resolution field-emission scanning electron microscope (SU8020, Hitachi, Japan).
4：Experimental Procedures and Operational Workflow
The fiber facet is first dipped into the colloid solution at a speed of 1000 μm/s and kept immersed for 3 s. Then, it is pulled out of the solution at a speed 250 μm/s, and kept suspended above the solution for 3 s. The total displacement was 0.5 mm. The initial position of the fiber facet was fixed at 0.15 - 0.2 mm above the solution surface.
5：Data Analysis Methods
Finite-difference time-domain (FDTD) method was used to calculate the near-field electric field distribution of the nanoparticle clusters. The SERS spectra were measured with a portable Raman spectrometer, using a laser excitation source with a wavelength of 785 nm.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
