Huang Cuiying, Li Hang, Zhang Xinping
School of Arts and Sciences, Fujian Medical University, Fuzhou, Fujian 350122, China.
Institute of Information Photonics Technology, Beijing University of Technology, Beijing 100124, China.
ACS Omega. 2024 Aug 22;9(35):37188-37196. doi: 10.1021/acsomega.4c04588. eCollection 2024 Sep 3.
Achieving a high-density, repeatable, and uniform distribution of "hotspots" across the entire surface-enhanced Raman scattering (SERS) substrate is a current challenge in facilitating the efficient preparation of large-area SERS substrates. In this study, we aim to produce homogeneous surface-enhanced Raman scattering (SERS) substrates based on the strong interaction between femtosecond laser pulses and a thin film of colloidal gold nanoparticles (AuNPs). The SERS substrate we obtained consists of irregularly shaped and sharp-edged gold nanoparticle aggregates with specially extruding features; meanwhile, a large number of three-dimensional AuNP stacks are produced. The advantages of such configurations lie in the production of a high density of hotspots, which can significantly improve the SERS performance. When the laser fluence is 5.6 mJ/cm, the substrate exhibits the best SERS enhancement effect, and a strong SERS signal can still be observed when testing the concentration of R6G at 10 mol/L. The enhancement factor of such SERS substrates prepared using femtosecond laser direct writing is increased by 3 orders of magnitude compared to the conventional furnace annealing process. Furthermore, the relative standard deviation for the intensities of the SERS signals was measured to be 5.1% over an area of 50 × 50 μm, indicating a highly homogeneous SERS performance and excellent potential for practical applications.
在整个表面增强拉曼散射（SERS）基底上实现“热点”的高密度、可重复且均匀分布，是当前促进大面积SERS基底高效制备的一项挑战。在本研究中，我们旨在基于飞秒激光脉冲与胶体金纳米颗粒（AuNP）薄膜之间的强相互作用来制备均匀的表面增强拉曼散射（SERS）基底。我们获得的SERS基底由形状不规则且边缘尖锐的金纳米颗粒聚集体组成，具有特殊的突出特征；同时，还产生了大量三维AuNP堆叠。这种结构的优势在于能产生高密度的热点，可显著提高SERS性能。当激光能量密度为5.6 mJ/cm时，该基底展现出最佳的SERS增强效果，在检测10 mol/L的R6G浓度时仍能观察到较强的SERS信号。与传统的炉退火工艺相比，利用飞秒激光直写制备的此类SERS基底的增强因子提高了3个数量级。此外，在50×50 μm的面积上测量得到的SERS信号强度的相对标准偏差为5.1%，表明其具有高度均匀的SERS性能以及出色的实际应用潜力。
