School of Mechatronics & Vehicle Engineering, East China Jiaotong University, Nanchang 330013, China.
Department of Optoelectronic Information Engineering, Zhejiang University, Hangzhou 310027, China.
Sensors (Basel). 2021 May 7;21(9):3238. doi: 10.3390/s21093238.
It is very important for human health to supervise the use of food additives, because excessive use of food additives will cause harm to the human body, especially lead to organ failures and even cancers. Therefore, it is important to realize high-sensibility detection of benzoic acid, a widely used food additive. Based on the theory of electromagnetism, this research attempts to design a terahertz-enhanced metamaterial resonator, using a metamaterial resonator to achieve enhanced detection of benzoic acid additives by using terahertz technology. The absorption peak of the metamaterial resonator is designed to be 1.95 THz, and the effectiveness of the metamaterial resonator is verified. Firstly, the original THz spectra of benzoic acid aqueous solution samples based on metamaterial are collected. Secondly, smoothing, multivariate scattering correction (MSC), and smoothing combined with first derivative (SG + 1 D) methods are used to preprocess the spectra to study the better spectral pretreatment methods. Then, Uninformative Variable Elimination (UVE) and Competitive Adaptive Reweighted Sampling (CARS) are used to explore the optimal terahertz band selection method. Finally, Partial Least Squares (PLS) and Least square support vector machine (LS-SVM) models are established, respectively, to realize the enhanced detection of benzoic acid additives. The LS-SVM model combined with CARS has the best effect, with the correlation coefficient of prediction set (R) is 0.9953, the root mean square error of prediction set (RMSEP) is 7.3 × 10, and the limit of detection (LOD) is 2.3610 × 10 g/mL. The research results lay a foundation for THz spectral analysis of benzoic acid additives, so that THz technology-based detection of benzoic acid additives in food can reach requirements stipulated in the national standard. This research is of great significance for promoting the detection and analysis of trace additives in food, whose results can also serve as a reference to the detection of antibiotic residues, banned additives, and other trace substances.
监督食品添加剂的使用对人类健康非常重要，因为过量使用食品添加剂会对人体造成伤害，特别是导致器官衰竭甚至癌症。因此，实现广泛使用的食品添加剂苯甲酸的高灵敏度检测非常重要。本研究基于电磁学理论，尝试设计了一种太赫兹增强超材料谐振器，利用超材料谐振器通过太赫兹技术实现对苯甲酸添加剂的增强检测。设计超材料谐振器的吸收峰为 1.95THz，并验证了超材料谐振器的有效性。首先，基于超材料收集苯甲酸水溶液样品的原始太赫兹光谱。其次，采用平滑、多元散射校正（MSC）和平滑加一阶导数（SG+1D）方法对光谱进行预处理，以研究更好的光谱预处理方法。然后，采用无信息变量消除（UVE）和竞争自适应重采样（CARS）方法探索最佳太赫兹波段选择方法。最后，分别建立偏最小二乘（PLS）和最小二乘支持向量机（LS-SVM）模型，实现苯甲酸添加剂的增强检测。LS-SVM 模型与 CARS 相结合效果最佳，预测集的相关系数（R）为 0.9953，预测集的均方根误差（RMSEP）为 7.3×10，检测限（LOD）为 2.3610×10g/mL。研究结果为苯甲酸添加剂的太赫兹光谱分析奠定了基础，使基于太赫兹技术的食品中苯甲酸添加剂的检测能够达到国家标准的要求。本研究对促进食品中痕量添加剂的检测和分析具有重要意义，其结果也可作为抗生素残留、禁用添加剂等痕量物质检测的参考。
