Noninvasive simultaneous monitoring of pH and depth using surface-enhanced deep Raman spectroscopy
Noninvasive simultaneous monitoring of pH and depth using surface-enhanced deep Raman spectroscopy
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DOI：
10.1002/jrs.5875
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发表时间：
2020-03-20
影响因子：
2.5
通讯作者：
Matousek, Pavel
中科院分区：
文献类型：
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作者：
Gardner, Benjamin;Stone, Nicholas;Matousek, Pavel
在这里，我们演示了同时恢复的多路复用的物理信息的表面增强拉曼散射（Sers）纳米粒子（pH值和深度）使用深拉曼光谱。如前所述，根据理论，由适当分离的光谱峰产生的非弹性散射光子可以在它们穿过的介质中表现出不同的光学性质。这些差异可以影响作为传输路径长度的函数的拉曼峰的相对强度;因此，信号产生的深度固有地编码在光谱中;假设目标聚集在单个深度或位置处，则可以容易地确定其深度。此外，拉曼光谱对样品的化学性质非常敏感，并且pH的变化不仅通过相关的质子化和去质子化而观察到峰强度的变化，而且还观察到光谱特征的偏移。在这里，我们表明，它是可以精确地预测的深度（均方根误差[RMSE] 5%）的Sers纳米粒子在散射介质（0.5%的intraperoid），同时也能够非侵入性监测同时的pH值水平（RMSE 0.2 pH单位）的介质周围的纳米粒子。这一点很重要，因为它表明纳米颗粒可用于报告包括其深度在内的多种物理特性。这为一系列新的应用开辟了途径，包括在体内临床环境中对癌症病变进行无创诊断和定位。
Here we demonstrate the simultaneous recovery of multiplexed physical information of surface-enhanced Raman scattering (SERS) nanoparticles (pH and depth) using deep Raman spectroscopy. As has been shown previously and in accordance with theory, inelastically scattered photons arising from spectral peaks that are suitably separated can exhibit different optical properties in the media through which they travel. These differences can impact the relative intensities of the Raman peaks as a function of the transmission path length; thereby, the depth of signal generation is inherently encoded in the spectra; assuming the target is clustered at a single depth or location, its depth can be readily determined. Moreover, Raman spectroscopy is very sensitive to chemistry of a sample, and changes in pH are observed not only as changes in peak intensity through relevant protonation and deprotonation but also as shifts in spectral features. Here, we show it is possible to precisely predict the depth (root-mean-square error [RMSE] 5 %) of SERS nanoparticles in scattering media (0.5% intralipid) while also being able to noninvasively monitor simultaneously the pH levels (RMSE 0.2 pH units) of the media surrounding the nanoparticles. This is important as it demonstrates that nanoparticles can be used to report on multiple physical properties including their depth. This opens avenues for a range of new applications including the noninvasive diagnosis and localisation of cancer lesions in clinical environment in vivo.