Liu Xiaoyu, Yuan Li, Wang Su, Fang Jinghuai
Nantong University, Nantong, Jiangsu, 226019, People's Republic of China.
Mikrochim Acta. 2025 Jun 13;192(7):426. doi: 10.1007/s00604-025-07255-1.
A gap-tunable Au/Ag cascaded polystyrene (PS) sphere array (Au/Ag CPSA) structure, leveraging the thermal expansion properties of polydimethylsiloxane (PDMS) for dynamic nanogap modulation to enhance SERS sensitivity is presented. The nanoarray was fabricated using vacuum thermal evaporation coating followed by chemical reduction. Its morphology was characterized via scanning electron microscopy (FE-SEM), while the electromagnetic field distribution was analyzed using finite difference time domain (FDTD) simulations. Under optimized conditions, the substrate achieved an enhancement factor (EF) of 1.3 × 10⁸ for crystal violet (CV) with a detection limit of 10⁻ M, while malachite green (MG) detection reached the ppm level. Furthermore, the dynamic gap modulation strategy significantly improved the adsorption efficiency of bovine serum albumin (BSA), achieving a detection limit of 5 ng/mL. The substrate also exhibited a relative standard deviation (RSD) below 10%, indicating excellent uniformity and stability. This work provides novel insights into SERS hotspot regulation and macromolecular detection, demonstrating significant potential for applications in biomedical diagnostics and environmental monitoring.
本文提出了一种间隙可调的金/银级联聚苯乙烯（PS）微球阵列（Au/Ag CPSA）结构，利用聚二甲基硅氧烷（PDMS）的热膨胀特性进行动态纳米间隙调制，以提高表面增强拉曼散射（SERS）灵敏度。该纳米阵列采用真空热蒸发镀膜和化学还原法制备。通过场发射扫描电子显微镜（FE-SEM）对其形貌进行表征，同时利用时域有限差分（FDTD）模拟分析其电磁场分布。在优化条件下，该基底对结晶紫（CV）的增强因子（EF）达到1.3×10⁸，检测限为10⁻⁸ M，而孔雀石绿（MG）检测达到ppm级别。此外，动态间隙调制策略显著提高了牛血清白蛋白（BSA）的吸附效率，检测限达到5 ng/mL。该基底的相对标准偏差（RSD）低于10%，表明具有优异的均匀性和稳定性。这项工作为SERS热点调控和大分子检测提供了新的见解，展示了其在生物医学诊断和环境监测中的巨大应用潜力。
