High-sensitivity terahertz scanner for detection of aflatoxins in nuts and nut products

项目总结/摘要 太赫兹波具有独特的规格，使其非常有吸引力的非侵入性，无标签 生物传感这是因为许多有机化合物对电磁波有独特的反应， 太赫兹频率此外，太赫兹波可以穿透许多光学不透明的环境 以及大多数包装材料，如塑料，纸张等，这些巨大的潜力使太赫兹 成像/光谱系统是高灵敏度、高通量和非破坏性的优秀平台 检测黄曲霉毒素，黄曲霉毒素可以在各种农产品中生长，并导致各种慢性健康 如果食用，包括肝癌。黄曲霉毒素在太赫兹波段具有独特的光谱特性 频率，然而，使用太赫兹波进行高通量和高灵敏度的黄曲霉毒素检测， 由于传统太赫兹扫描仪的低灵敏度，食品在以前似乎不实用， 其遭受信噪比（SNR）和测量时间之间的折衷。比如说， 以达到足够灵敏的测量来检测黄曲霉毒素污染的最大允许水平 由食品和药物管理局（FDA）监管的传统太赫兹扫描仪， 测量应在相同的样品上进行，以减少所获取的数据的噪声， 测量时间很长。此外，大多数太赫兹光谱测量应该是 以非常细致的方式进行，这需要特定的样品制备配方， 用于现场设置。拟议的研究解决了传统太赫兹扫描系统的这些局限性 并提供了一种高通量、非破坏性和高灵敏度的黄曲霉毒素扫描仪， 熟练的用户操作。实现这种高性能黄曲霉毒素扫描仪的关键创新是：（1） 使用突破性的等离子体太赫兹源和检测器技术， 与传统太赫兹设备提供的SNR水平相比，SNR水平更高，（2）使用 先进的数据分析算法，能够直接计算黄曲霉毒素浓度，而不管 被测样品的类型和形状。因此，所提出的太赫兹扫描仪提供了一个很好的 用于高通量、非破坏性、非接触检测坚果和加工食品中黄曲霉毒素的监管工具 坚果产品，最大限度地减少监管违规风险，并为公众提供高质量的产品。通过 在第一阶段结束时，将完成对黄曲霉毒素片剂和黄曲霉毒素的彻底实验分析- 受污染的坚果与单像素太赫兹扫描仪原型，以评估的灵敏度和特异性， 扫描仪建议在第二阶段，黄曲霉毒素扫描率将通过使用焦平面探测器阵列来提高， 我们将把已发展的多像素扫描器用于检测黄曲霉毒素， 农业食品，同时开发可用于实际领域/包装/分销的原型 设置.

Project Summary/Abstract Terahertz waves have unique specifications that make them very attractive for non-invasive, label-free biosensing. This is because many organic compounds have unique responses to the electromagnetic waves at terahertz frequencies. In addition, terahertz waves can penetrate through many optically-opaque environments as well as most of the packaging materials such as plastic, paper, etc. These great potentials make terahertz imaging/spectroscopy systems an excellent platform for high-sensitivity, high-throughput, and non-destructive detection of aflatoxins, which can grow in various agricultural food products and cause various chronic health problems if consumed, including liver cancer. Aflatoxins have unique spectral characteristics at terahertz frequencies, however the use of terahertz waves for high-throughput and high-sensitivity aflatoxin detection in food products did not seem practical before because of the low sensitivity of conventional terahertz scanners, which suffer from a trade-off between the signal-to-noise ratio (SNR) and the measurement time. For instance, to achieve a sufficiently sensitive measurement to detect the maximum allowed aflatoxin contamination level regulated by the Food and Drug Administration (FDA) with conventional terahertz scanners, more than thousand measurements should be taken on the same sample to reduce the noise of the acquired data, which increases the measurement time significantly. In addition, most of the terahertz spectroscopy measurements should be performed in very meticulous ways, which require specific sample preparation recipes that are not appropriate for field settings. The proposed research addresses these limitations of conventional terahertz scanning systems and offers a high-throughput, non-destructive, and highly-sensitive aflatoxin scanner that does not require a skilled user to operate. The key innovations that enable such a high-performance aflatoxin scanner are: (1) the use of a breakthrough plasmonic terahertz source and detector technology that offers several orders of magnitude higher SNR levels compared to those offered by conventional terahertz devices, (2) the use of an advanced data analysis algorithm that is capable of direct calculation of aflatoxin concentration regardless of the type and shape of the sample under test. As a result, the proposed terahertz scanner offers an excellent regulatory tool for high-throughput, non-destructive, non-contact detection of aflatoxins in nuts and processed nut products, minimizing regulatory non-compliance risks and providing high-quality products to the public. By the end of the Phase I, a thorough experimental analysis will be completed on aflatoxin tablets and aflatoxin- contaminated nuts with a single-pixel terahertz scanner prototype to assess the sensitivity and specificity of the proposed scanner. In Phase II, the aflatoxin scan rate will be boosted by using focal plane detector arrays and the use of the developed multi-pixel scanner for detection of aflatoxins will be extended to a wider range of agricultural food products, while developing a prototype that can be used in realistic field/packaging/distribution settings.