太赫兹技术在农产品检测中的应用研究进展

我国是农业大国，保障粮食安全是国家发展的战略需要。农产品检测技术的应用和发展对监控质量，预防由农产品品质问题引发的安全事故至关重要。太赫兹（Terahertz，THz）波位于电磁频谱空隙，频率高于微波而低于红外线，具备光子能量低、穿透性好、能表征分子结构等优点。基于太赫兹波的光谱检测技术受到研究人员广泛关注，在生物医学、安全检查等方面得到应用，被证明是一种可靠的检测手段。在农产品应用领域，太赫兹波特有的非接触、无标记检测能力为农产品成分分析、质量控制提供了技术手段，其良好的穿透性和无损害性，可以用来在不破坏农产品表面及外包装的前提下，检测内部成分变化。与其他光谱（超声、X射线、红外等）检测手段相比，太赫兹波频率范围宽、表征能力强，可实现对目标物质的快速无损检测。近几年，随着太赫兹发射源、探测器等设备以及光谱和成像技术的发展，其在农产品领域的应用有了新的进展。通过收集整理近期的文献资料，综述了太赫兹技术在农产品检测方面的应用拓展和研究成果，总结了目前存在的应用局限。在此基础上，对未来太赫兹光谱和图像检测的研究方向进行了展望，提出提高检测灵敏度和检测速度是农产品领域太赫兹技术产业化应用的研究重点。在检测系统中引入基于超材料的传感器是提升灵敏度的一种有效手段，可以突破原有的太赫兹光谱检测极限，对研究农药残留、真菌毒素等危害农产品安全的痕量污染物具有重要意义。在农产品快速成像检测方面，基于单像素成像和压缩感知理论的太赫兹计算成像技术是提高检测速度的可行方案。这些研究成果将为后续太赫兹技术的发展提供方向性指导，对农产品检测领域的应用推广具有重要参考价值。

Application Progress of Terahertz Technology in Agriculture Detection

China is a big agricultural country, and ensuring food security is a strategic need for national development. The application and development of agricultural product detection are crucial for quality control and avoiding safety accidents caused by quality problems. Terahertz (THz) wave is located in the gap between the microwave and infrared regions of the electromagnetic spectrum, the frequency of which is higher than a microwave but lower than infrared and has low photon energy, good penetration, as well as can be used to characterize the molecular structure. The detection technology based on terahertz has been applied in bio-medicine, safety inspection and other fields and has been proved to be a reliable detection method. For agricultural products, the terahertz wave’s unique untouched and label-free capability provides a method for composition analysis and quality control. Based on its penetration and non-destructive, the terahertz spectrum is also used to detect the internal ingredients without damaging agricultural products’ surface and outer packaging. Compared with other spectral detection technologies(ultrasonic, X-ray, infrared, etc.), terahertz wave is in a wide frequency range with a good characteristic spectrum and can be used for rapid non-destructive detection. In recent years, with the development of THz sources, THz detectors, THz spectroscopy and imaging technology, the application of terahertz in agricultural products detection has further development. Through collecting and sorting out recent relevant information, this paper reviewed the new progress of terahertz technology in agricultural product detection, summarized the limitation of terahertz application, and discussed the future study direction of terahertz spectrum and imaging——improving sensitivity and accelerating detection speed are research focuses for industrialization application of terahertz detection technology. The metamaterial-based sensors are applied in the terahertz detection system to improve the detection sensitivity, which is of great significance to detecting pesticides, mycotoxins and other pollutants that harm the safety of agricultural products. The terahertz computational imaging technology based on single-pixel imaging and compressed sensing algorithm is a feasible solution to accelerate the detection speed in the rapid imaging detection of agricultural products. These researches provide direction for the subsequent development of terahertz technology and offer an important reference for the application promotion of agricultural products terahertz detection.