Laboratory of Advanced Materials, Department of Materials Science, Fudan University, Shanghai 200438, China.
Department of Chemistry, State University of New York at Binghamton, Binghamton, NY 13902, USA.
Sensors (Basel). 2021 Dec 14;21(24):8345. doi: 10.3390/s21248345.
The exploration of the plasmonic field enhancement of nanoprobes consisting of gold and magnetic core@gold shell nanoparticles has found increasing application for the development of surface-enhanced Raman spectroscopy (SERS)-based biosensors. The understanding of factors controlling the electromagnetic field enhancement, as a result of the plasmonic field enhancement of the nanoprobes in SERS biosensing applications, is critical for the design and preparation of the optimal nanoprobes. This report describes findings from theoretical calculations of the electromagnetic field intensity of dimer models of gold and magnetic core@gold shell nanoparticles in immunoassay SERS detection of biomarkers. The electromagnetic field intensities for a series of dimeric nanoprobes with antibody-antigen-antibody binding defined interparticle distances were examined in terms of nanoparticle sizes, core-shell sizes, and interparticle spacing. The results reveal that the electromagnetic field enhancement not only depended on the nanoparticle size and the relative core size and shell thicknesses of the magnetic core@shell nanoparticles but also strongly on the interparticle spacing. Some of the dependencies are also compared with experimental data from SERS detection of selected cancer biomarkers, showing good agreement. The findings have implications for the design and optimization of functional nanoprobes for SERS-based biosensors.
由金和磁核@金壳纳米粒子组成的纳米探针的等离子体场增强的探索在基于表面增强拉曼光谱（SERS）的生物传感器的发展中得到了越来越多的应用。了解控制电磁场增强的因素，是 SERS 生物传感应用中纳米探针等离子体场增强的结果，对于最佳纳米探针的设计和制备至关重要。本报告描述了在免疫测定 SERS 检测生物标志物中，对金和磁核@金壳纳米粒子二聚体模型的电磁场强度进行理论计算的结果。根据纳米颗粒尺寸、核壳尺寸和颗粒间间距，研究了一系列具有抗体-抗原-抗体结合定义的颗粒间距离的二聚体纳米探针的电磁场强度。结果表明，电磁场增强不仅取决于纳米颗粒的尺寸以及磁核壳纳米粒子的相对核尺寸和壳厚度，而且还强烈依赖于颗粒间的间距。一些依赖性也与 SERS 检测选定癌症生物标志物的实验数据进行了比较，显示出良好的一致性。这些发现对基于 SERS 的生物传感器的功能性纳米探针的设计和优化具有重要意义。
