为了快速检测水溶液、 尿液和血清中的咪达唑仑, 建立了一种基于表面增强拉曼光谱(SERS)技术的检测方案。 使用BWS415-785H型便携式拉曼光谱仪采集了拉曼光谱, 其激发光波长为785 nm, 光谱测量范围为68～2 700 cm-1, 光谱分辨率小于3 cm-1, 激光功率为80 mW, 积分时间为5 s。 首先通过密度泛函理论对咪达唑仑的拉曼光谱进行了计算, 并与实验值进行对比, 对拉曼峰进行了归属。 然后以银溶胶作为表面增强基底, 以硫酸镁(MgSO4)水溶液作为促凝剂, 选取689和827 cm-1处的拉曼峰作为特征峰, 对咪达唑仑进行了SERS检测。 在水溶液中咪达唑仑的检测限为6 μg·mL-1, 在5～40 μg·mL-1浓度范围内, 拉曼特征峰的强度随咪达唑仑水溶液浓度的线性曲线方程为y=188.18x-743.05, 相关系数为r=0.972, 回收率范围为98.2%~107.2%, RSD范围为2.08%~3.25%。 在尿液中咪达唑仑的检测限为20 μg·mL-1, 在20~125 μg·mL-1浓度范围内, 拉曼特征峰的强度随咪达唑仑尿液浓度的线性曲线方程为y=59.78x-640.71, 相关系数为r=0.958, 回收率范围为96.9%~107.9%, RSD范围为4.45%~5.75%。 在血清中咪达唑仑的检测限为20 μg·mL-1, 在15~125 μg·mL-1浓度范围内, 拉曼特征峰的强度随咪达唑仑血清浓度的线性曲线方程为y=30.81x+176.66, 相关系数为r=0.963, 回收率范围为94.2%~105.7%, RSD范围为3.60%~4.41%。 该方法具有快速、 准确、 无损、 操作简便等优点, 为咪达唑仑的现场快速检测打下了良好的基础。

Midazolam in aqueous solution, urine and serum were rapidly detected on site, based on surface-enhanced Raman spectroscopy (SERS) technology in this paper. The Raman spectra were recorded by a portable laser Raman spectrometer BWS415-785H with a wavelength of 785 nm. The spectrometer provided that the spectral measurement range would be 68～2 700 cm-1 and spectral resolution would be better than 3 cm-1. The output power was maintained 80 mW in the experiment with 5 s of integration time. First, the Raman spectra of Midazolam were calculated by density functional theory and compared with the experimental values. The possible characteristic peaks were identified. Then, using silver nanoparticles as active substrate, MgSO4 aqueous solution as neutral salt coagulants, the Raman peak at 689 and 827 cm-1 was selected as the characteristic peak on detection, the SERS detection of Midazolam was conducted. The limit of detection of Midazolam in aqueous solution samples is 6 μg·mL-1. In the range of concentrations of 5～40 μg·mL-1, the relationship of Raman peak intensity and concentration of Midazolam in aqueous solution can be expressed by a linear equation that was y=188.18x+743.05. The correlation coefficient was r=0.972, the recovery was 98.2%～107.2%, and the relative standard deviation (RSD) was 2.08%～3.25%. The limit of detection of Midazolam in urine samples is 20 μg·mL-1, In the range of concentrations of 15～125 μg·mL-1, the relationship of Raman peak intensity and concentration of Midazolam in urine can be expressed by a linear equation: y=59.78x-640.71. The correlation coefficient was r=0.958, the recovery was 96.9%～107.9%, and the RSD was 4.45%～5.75%. The limit of detection of Midazolam in serum samples is 20 μg·mL-1, In the range of concentrations of 15～125 μg·mL-1, the relationship of Raman peak intensity and concentration of Midazolam in serum can be expressed by a linear equation: y=30.81x+176.66. The correlation coefficient was r=0.963, the recovery was 94.2%～105.7%, and the RSD was 3.60%～4.41%. This method is rapid, accurate, non-destructive and easy to operate, and it lays a good foundation for Midazolam detection in the field.