Surface-enhanced IR absorption spectroscopy in attenuated-total reflection（ATR-SEIRAS） configuration was extended for the first time to a cadmium electrode with the adsorption of pyridine as the model system. The SE...Surface-enhanced IR absorption spectroscopy in attenuated-total reflection（ATR-SEIRAS） configuration was extended for the first time to a cadmium electrode with the adsorption of pyridine as the model system. The SEIRAS active Cd film electrode was prepared by electrodeposition of Cd mulitlayers onto a underlying Au nanofilm on Si in 0.01 mol/L CdSO 4 +0.1 mol/L KClO 4. The morphology of the as-prepared Cd film exhibits an island structure. In the potential range of -1.2 to -0.8 V（vs. SCE）, only in-plane vibrations belonging to the A1 symmetry were detected whereas those to the B1 symmetry virtually were not, suggesting that pyridine coordinates vertically or at a little angle to the Cd electrode surface via its nitrogen end without edge-tilted rotation of its ring plane. The Py adsorption configuration is closed to that found on a Au electrode, but different from that on a Ni or Pt electrode, which may be assigned to different structures of valence electron shells for the substrate metals.展开更多
目的在近红外光谱(near infrared spectroscopy,NIR)与表面增强拉曼光谱(surface-enhanced Raman spectroscopy,SERS)特征层数据融合的基础上构建偏最小二乘回归(partial least squares regression,PLSR)模型实现花生油中黄曲霉毒素B_(1...目的在近红外光谱(near infrared spectroscopy,NIR)与表面增强拉曼光谱(surface-enhanced Raman spectroscopy,SERS)特征层数据融合的基础上构建偏最小二乘回归(partial least squares regression,PLSR)模型实现花生油中黄曲霉毒素B_(1)(aflatoxin B_(1),AFB_(1))含量的快速检测。方法首先,分别采集待测样本的NIR与SERS光谱。其次,将采集的NIR与SERS光谱分别进行光谱预处理。然后,采用基于希尔伯特-施密特独立准则的变量空间迭代优化算法(Hilbert-Schmidt independence criterion based variable space iterative optimization,HSIC-VSIO)分别筛选NIR与SERS光谱的特征变量。最后,将筛选的特征变量进行融合并构建PLSR模型用于定量检测花生油中AFB_(1)含量。结果与NIR光谱数据、SERS光谱数据以及NIR与SERS光谱直接融合数据构建的PLSR模型相比,NIR与SERS光谱特征层融合数据构建的PLSR模型具有最佳的预测性能:校正集均方根误差(root mean squared error of calibration set,RMSEC)为0.1569,校正集决定系数(coefficient of determination of calibration set,R_(c)^(2))为0.9908,预测集均方根误差(root mean squared error of prediction set,RMSEP)为0.1827,预测集决定系数(coefficient of determination of prediction set,R_(c)^(2))为0.9854,性能偏差比(ratio of performance to deviation,RPD)为8.2761。将本方法与标准方法分别检测真实含有AFB_(1)的花生油样本,结果表明两者的检测性能无显著性差异(P=0.84>0.05)。结论本方法可实现花生油中AFB_(1)含量的快速、高精度定量检测,也验证了NIR与SERS光谱融合的可行性与有效性。展开更多
Mutual coupling of surface electromagnetic wave between different silver particles onsilver island substrates is realized experimentally and its effect on surface enhanced infrared spec-troscopy is studied. Silvcr isl...Mutual coupling of surface electromagnetic wave between different silver particles onsilver island substrates is realized experimentally and its effect on surface enhanced infrared spec-troscopy is studied. Silvcr island substrates of different size and distribution of silver particleshave been prepared by the vacuum evaporation and rapid thermal annealing, and characterizedby atomic force microscopy (AFM) and UV-visiblc spectroscopy. The surface enhanced infraredspectra of 4-Octyl-4’-(3-carboxy-trimethylene -oxy)-azobenzene (referred as ABD) LB monolayerare studied on such silver island films. The results elucidates the important role of the coupling ofsurface electromagnetic wave between silver particles in surface enhanced infrared spectroscopy.展开更多
文摘Surface-enhanced IR absorption spectroscopy in attenuated-total reflection（ATR-SEIRAS） configuration was extended for the first time to a cadmium electrode with the adsorption of pyridine as the model system. The SEIRAS active Cd film electrode was prepared by electrodeposition of Cd mulitlayers onto a underlying Au nanofilm on Si in 0.01 mol/L CdSO 4 +0.1 mol/L KClO 4. The morphology of the as-prepared Cd film exhibits an island structure. In the potential range of -1.2 to -0.8 V（vs. SCE）, only in-plane vibrations belonging to the A1 symmetry were detected whereas those to the B1 symmetry virtually were not, suggesting that pyridine coordinates vertically or at a little angle to the Cd electrode surface via its nitrogen end without edge-tilted rotation of its ring plane. The Py adsorption configuration is closed to that found on a Au electrode, but different from that on a Ni or Pt electrode, which may be assigned to different structures of valence electron shells for the substrate metals.
文摘目的在近红外光谱(near infrared spectroscopy,NIR)与表面增强拉曼光谱(surface-enhanced Raman spectroscopy,SERS)特征层数据融合的基础上构建偏最小二乘回归(partial least squares regression,PLSR)模型实现花生油中黄曲霉毒素B_(1)(aflatoxin B_(1),AFB_(1))含量的快速检测。方法首先,分别采集待测样本的NIR与SERS光谱。其次,将采集的NIR与SERS光谱分别进行光谱预处理。然后,采用基于希尔伯特-施密特独立准则的变量空间迭代优化算法(Hilbert-Schmidt independence criterion based variable space iterative optimization,HSIC-VSIO)分别筛选NIR与SERS光谱的特征变量。最后,将筛选的特征变量进行融合并构建PLSR模型用于定量检测花生油中AFB_(1)含量。结果与NIR光谱数据、SERS光谱数据以及NIR与SERS光谱直接融合数据构建的PLSR模型相比,NIR与SERS光谱特征层融合数据构建的PLSR模型具有最佳的预测性能:校正集均方根误差(root mean squared error of calibration set,RMSEC)为0.1569,校正集决定系数(coefficient of determination of calibration set,R_(c)^(2))为0.9908,预测集均方根误差(root mean squared error of prediction set,RMSEP)为0.1827,预测集决定系数(coefficient of determination of prediction set,R_(c)^(2))为0.9854,性能偏差比(ratio of performance to deviation,RPD)为8.2761。将本方法与标准方法分别检测真实含有AFB_(1)的花生油样本,结果表明两者的检测性能无显著性差异(P=0.84>0.05)。结论本方法可实现花生油中AFB_(1)含量的快速、高精度定量检测,也验证了NIR与SERS光谱融合的可行性与有效性。
文摘Mutual coupling of surface electromagnetic wave between different silver particles onsilver island substrates is realized experimentally and its effect on surface enhanced infrared spec-troscopy is studied. Silvcr island substrates of different size and distribution of silver particleshave been prepared by the vacuum evaporation and rapid thermal annealing, and characterizedby atomic force microscopy (AFM) and UV-visiblc spectroscopy. The surface enhanced infraredspectra of 4-Octyl-4’-(3-carboxy-trimethylene -oxy)-azobenzene (referred as ABD) LB monolayerare studied on such silver island films. The results elucidates the important role of the coupling ofsurface electromagnetic wave between silver particles in surface enhanced infrared spectroscopy.
