Two-Color iSCAT Imaging of Ag Nanoparticles Resolves Size and Ambient Refractive Index Changes.
Two-Color iSCAT Imaging of Ag Nanoparticles Resolves Size and Ambient Refractive Index Changes.
复制标题
银纳米粒子的双色 iSCAT 成像解决了尺寸和环境折射率的变化。
DOI：
10.1021/acs.nanolett.3c01306
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发表时间：
2023
期刊：
影响因子：
10.8
通讯作者：
Reinhard,BjörnM
中科院分区：
文献类型：
--
作者：
Velasco,Leslie;Ouyang,Tianhong;Reinhard,BjörnM
辨别具有不同尺寸和在具有不同折射率的环境介质中的贵金属纳米颗粒（NPs）的能力在成像和传感中具有重要的应用。在此，应用双色（405 nm，445 nm）干涉散射（iSCAT）检测方案来表征具有10、20、40和60 nm标称直径的Ag NP的波长依赖性iSCAT对比度，并区分不同尺寸的NP。iSCAT对比度还取决于环境折射率，并且当环境折射率从mn = 1.3892 ton= 1.4328增加时，两个通道上的相对iSCAT对比度揭示了40和60 nm Ag NP的光谱红移。然而，对于所选择的波长通道，双色成像策略的光谱分辨率不足以解决由10和20 nm Ag NP的折射率变化引起的光谱偏移。
The ability to discern noble metal nanoparticles (NPs) with different sizes and in ambient media with different refractive indices has important applications in imaging and sensing. Here a two-color (405 nm, 445 nm) interferometric scattering (iSCAT) detection scheme is applied to characterize the wavelength-dependent iSCAT contrast of Ag NPs with nominal diameters of 10, 20, 40, and 60 nm and to distinguish between NPs of different sizes. The iSCAT contrast also depends on the ambient refractive index and the relative iSCAT contrast on both channels revealed a spectral red-shift for 40 and 60 nm Ag NPs when the ambient refractive index was increased fromn= 1.3892 ton= 1.4328. With the selected wavelength channels, the spectral resolution of the two-color imaging strategy was, however, insufficient to resolve spectral shifts induced by refractive index changes for 10 and 20 nm Ag NPs.