Cholesterol is an essential molecule for many processes in the human body and many diseases such as hypertension, coronary heart disease, atherosclerosis, and lipid metabolism dysfunction can be detected in their early stages by monitoring intracellular cholesterol levels. Herein, metallic surface‐enhanced Raman scattering (SERS) core–shell nanoparticles with an embedded standard are designed for nondestructive detection of H₂O₂ and cholesterol. A classical least squares (CLS) spectral fitting method allows one to accurately extract the SERS signals of internal standards and target molecules from the multiplexed spectra. The embedded internal standard can be used to calibrate the SERS signals, removing fluctuations induced by differing measurement conditions and local states of the nanoparticles, such as aggregation. Thus, SERS signal reproducibility is improved and a better linear relationship in the working curve of detection is achieved. Using these SERS nanoprobes quantitative detection of H₂O₂ and cholesterol in solution and inside live cells at a single‐cell level is demonstrated.

中文翻译：

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具有增强胆固醇定量检测功能的嵌入式标准表面增强拉曼纳米探针

胆固醇是人体许多过程的必需分子，通过监测细胞内胆固醇水平，可以在早期发现许多疾病，例如高血压，冠心病，动脉粥样硬化和脂质代谢功能障碍。在此，具有嵌入式标准品的金属表面增强拉曼散射（SERS）核壳纳米粒子被设计用于H ₂ O _2的无损检测。和胆固醇。一种经典的最小二乘（CLS）光谱拟合方法可让您从多重光谱中准确提取内标物和目标分子的SERS信号。嵌入式内标可用于校准SERS信号，消除由不同的测量条件和纳米颗粒的局部状态（例如聚集）引起的波动。因此，改善了SERS信号的再现性，并且在检测的工作曲线中获得了更好的线性关系。使用这些SERS纳米探针，可以在单细胞水平上定量检测溶液和活细胞内部的H ₂ O ₂和胆固醇。