Recent Developments in Human Odor Detection Technologies

Human odor detection technologies have drawn attention due to the wide possibility of potential applications they open up in areas such as biometrics, criminal investigation and forensics, search for survivors under rubble, and security checkpoint screening. Gas chromatography/mass spectrometry (GC/MS) has been the most successful and powerful analytical approach developed to date for human odor analysis, and hundreds of human odorants have been identified using this tool. GC/MS has already enabled a good understanding to be obtained regarding human odor composition. Over the past two decades, research and development of E-nose technologies has accelerated at a fast pace, and in time may provide a complementary technology to those based on GC/MS. During the past several years, proof of concept has been demonstrated on the application of E-noses for real-time human odor detection and classification. In this review, the current state of technologies will be given on human odor analysis, detection, and classification, along with a discussion of each technology with a specific focus on recent developments. Technologies covered in this article include: various E-nose technologies; as well as gas chromatography integrated with mass spectrometry, ion mobility spectrometry, or other gas detectors. Other technologies will also be described such as optical sensors that have recently emerged for human odor detection, and the possibilities of exploiting absorbance spectroscopy and hyperspectral imaging.