A Fast-Response Odor Detector for Food Analysis

挥发性有机化合物（VOC）是一大类在正常温度和压力条件下容易蒸发的有机化学物质。挥发性有机化合物在大气中的排放来自各种各样的自然和人为来源。 从生物医学诊断、国土安全、食品安全和质量到环境保护，对不同来源排放的VOC进行表征和监测非常重要。 该提案旨在开发一种基于电子鼻原理的新型现场实时气味传感器。 这项研究的结果将对降低成本，增加便携性，提高分析速度和分辨率的当前VOC检测方法产生重大影响。 该设备将通过结合微技术，化学和统计学来开发，并将被验证用于食品掺假的高分辨率检测，这是一个严重而普遍的全球性问题。 这项研究在推动科学和技术满足社会需求的同时，将为学生提供宝贵的经验，因为他们将接受培训，在跨学科的环境中工作。此外，推广活动将教育大学预科学生如何先进的科学和工程可以合并，以解决真实的，当前的problem. Objective拟议的研究是发展快速气味检测器的实施合并到一个小的足迹在电子鼻和快速气相色谱（GC）的重要概念。该系统的重点是独特设计的色谱芯片与多个毛细管并行工作。 该芯片将使用微机电系统（MEMS）技术在硅中制造，并将使用离子液体进行功能化。主要的工艺步骤包括深反应离子刻蚀，然后是硅-玻璃阳极键合。所提出的色谱芯片将与一个或多个检测器接口，以生成样品的快速气味印记。 输出将是一系列色谱响应，将使用先进的多元统计和模式识别算法进行分析，以确定食品样品是否掺假。 该统计方法可以同时进行非加性多变量非参数模型的变量选择，用于分析芯片产生的大量数据。 橄榄油和蜂蜜是掺假的目标，将用于验证该技术。 预计新的气味检测器将实现不到一分钟的总分析时间，这是数量级更快，更经济的相比，建立技术，如气相色谱-质谱（GC/MS）。

Volatile organic compounds (VOCs) constitute a large group of organic chemicals that evaporate easily under normal conditions of temperature and pressure. VOCs are emitted in the atmosphere from a wide variety of natural and anthropogenic sources. The characterization and monitoring of VOCs emitted from different sources is immensely important ranging from biomedical diagnostics, homeland security, food safety and quality to environmental protection. The proposal seeks to develop a new on-site real-time odor sensor based on the principle of electronic noses. The outcome of this proposed research will have a significant impact on reducing the cost, increasing the portability, and increasing the analysis speed and resolution of current VOC detection methodologies. The proposed device will be developed by combining microtechnology, chemistry, and statistics and will be validated for high resolution detection of food adulteration which is a serious and widespread global issue. The research while advancing science and technology for a societal need, will provide invaluable experience for students as they will be trained to work in an interdisciplinary environment. Furthermore, the outreach activities will educate pre-college students how advanced science and engineering can be merged to solve real, current problems.The objective of the proposed research is to develop rapid odor detector implemented by merging the significant concepts in electronic noses and fast gas chromatography (GC) into a small footprint. The focus of this system is the uniquely designed chromatographic chip with multiple capillaries working in parallel. The chip will be fabricated in silicon using microelectromechanical systems (MEMS) technology and will be functionalized using ionic liquids. The major processing steps include deep reactive ion etching followed by silicon-glass anodic bonding. The proposed chromatographic chip will be interfaced with a detector or multiple detectors to generate a rapid odor-print of the sample. The output will be an array of chromatographic responses which will be analyzed using advanced multivariate statistical and pattern recognition algorithms to determine if the food sample has been adulterated. The statistical method can simultaneously perform a variable selection in nonadditive multivariate nonparametric model for analyzing the large data generated by the chip. Olive oil and honey which have been the target of adulteration will be used to validate the technology. It is expected that the new odor detector will achieve a total analysis time of less than a minute which is orders of magnitude faster and more economical when compared to established techniques such as gas chromatography-mass spectrometry (GC/MS).