基于表面增强拉曼光谱技术(surface enhanced Raman spectroscopy, SERS), 研制出对食品中乌洛托品进行现场快速分析检测的系统。 检测系统由多功能前处理模块、 拉曼光学模块、 嵌入式主控模块三部分组成, 实现了待测样品的前处理, 拉曼光谱数据的产生、 收集、 传输与处理。 其中, 多功能前处理模块将化学实验中经常用到的离心、 超声、 挥发三种功能集于一体, 精简了前处理实验中需要用到的设备; 拉曼光学模块采用探头光路与分光系统合为一体的整体式设计, 并在探头光路中使用数值孔径为06的非球面透镜, 同时利用交叉非对称Czerny-Turner结构对分光系统进行了设计; 嵌入式主控模块采用自主研发的FPGA+ARM双核心主控电路, 配合CCD的制冷电路与驱动电路, 搭载μC/OS-Ⅲ操作系统, 实现了对CCD上拉曼光谱数据的采集、 传输与处理。 利用柠檬酸钠制备纳米金(liquid colloidal gold nanoparticle, LCP-1)作为增强试剂对乌洛托品进行检测, 将乌洛托品的拉曼特征峰选取在1 047 cm-1处, 对乌洛托品标准品和含有乌洛托品的腐竹与米粉样品进行检测实验, 实验结果表明所设计的检测系统可以实现对乌洛托品的准确识别, 对乌洛托品标准品的检测限可达001 mg·L-1, 对腐竹和米粉样品中乌洛托品的检出限可达05 mg·L-1, 检测时间小于20 min, 实现了食品中乌洛托品的现场快速检测。

Based on surface enhanced Raman spectroscopy (SERS) technology, the detection system for rapid fild determination of urotropine in food is proposed. The detecting system consists of multifunctional pretreating module, Roman optical module and embedded master control module. It completed the pretreatment of sample, the generation, collection and transmission of the Raman spectral data. The multifunctional pretreating module integrate centrifuge, ultrasound and volatile functions all together, reducing the equipments used in the pretreatment experiment. Besides, it is portable and convenient for operation. The Roman optical module we designed embodies the probe of Raman spectrometer and monochromator, and the numerical aperture of the aspherical lens we used in the optical system of the probe was 06. Besides, the monochromator was designed based on Asymmetrical crossed Czerny-Turner structure. The hardware part of the embedded master control module is made up of ARM and FPGA, and its peripheral circuits. The software part of the module is made up of real time operation system μC/OS-Ⅲ, graphics library emWin, file system FatFs and various types of equipment components. Thus, accomplished the collection, transmission and calculation of the Raman spectral data from CCD. The liquid colloidal gold nanoparticle (LCP-1) was used in the detection experiments of urotropine, while the characteristic peaks at 1 047 cm-1 was chosen as the identity information of urotropine. The result of detection experiments shows that the system has the ability to identify the urotropine accurately, the detection limit of urotropine standards was 001 mg·L-1, with detection limit of urotropine in yuba and rice-noodle was 05 mg·L-1. Besides, the testing time was less than 20 minutes,which meets the requirements for rapid field determination of urotropine in food．