Vu Tung Duy, Sohng Woosuk, Jang Eunjin, Choi Dongho, Chung Hoeil
Department of Chemistry and Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea.
Analyst. 2021 Feb 7;146(3):1091-1098. doi: 10.1039/d0an02115f. Epub 2020 Dec 22.
Voltage-applied SERS measurement of bile juice in conjunction with two-trace two-dimensional (2T2D) correlation analysis was demonstrated as a potential tool to enhance discrimination of gall bladder (GB) stone and GB polyp. When SERS spectra of the aqueous phases extracted from raw bile juice samples were measured with applying external voltage from -300 to +300 mV (100 mV intervals), subsequent spectral variations of the adsorbed components (bilirubin-containing compounds) on the SERS substrate were minute, and discrimination of the two GB diseases in a principal component score domain was difficult. Therefore, 2T2D correlation analysis, effectively identifying asynchronous (dissimilar) spectral behaviors in the voltage-induced SERS spectra, was used to improve the discrimination. When two spectra of a sample collected with application of +100 and +300 mV were adopted, the features of subsequent 2T2D slice spectra were characteristic, and discrimination of GB stone and GB polyp substantially improved. External voltage application and recognition of the voltage-induced spectral features by 2T2D correlation analysis were key factors for the improvement. Since the demonstrated method relied on only a few SERS-active compounds, infrared (IR) spectroscopy featuring all the present components in the samples was also evaluated for comparison. However, the IR-based discrimination was inferior because the metabolite compositions in the samples between the GB diseases were not noticeably different.
结合双迹二维（2T2D）相关分析的外加电压表面增强拉曼光谱（SERS）对胆汁进行测量，被证明是一种增强胆囊（GB）结石和GB息肉鉴别能力的潜在工具。当对从生胆汁样品中提取的水相进行SERS光谱测量时，施加-300至+300 mV（间隔100 mV）的外部电压，SERS基底上吸附成分（含胆红素化合物）的后续光谱变化很小，在主成分得分域中难以区分这两种GB疾病。因此，2T2D相关分析用于改善鉴别，该分析能有效识别电压诱导SERS光谱中的异步（不同）光谱行为。当采用施加+100 mV和+300 mV时采集的样品的两个光谱时，后续2T2D切片光谱的特征具有特异性，GB结石和GB息肉的鉴别能力大幅提高。施加外部电压以及通过2T2D相关分析识别电压诱导的光谱特征是改善鉴别的关键因素。由于所展示的方法仅依赖少数SERS活性化合物，还对能够呈现样品中所有现有成分的红外（IR）光谱进行了评估以作比较。然而，基于IR的鉴别效果较差，因为GB疾病之间样品中的代谢物组成没有明显差异。
