Volatile organic compound sensing: Conventional to advanced approaches

Exhaled breath analysis is gaining significant attention among researchers due to its non-invasive potential in early diagnosis and disease monitoring. Volatile organic compounds (VOCs) present in exhaled breath can provide useful information on the metabolic and biological processes occurring within the human body. Some VOCs in exhaled human breath have been identified as biomarkers and excess amounts of these VOCs are considered indicative of various associated diseases. Gas chromatography-mass spectrometry (GC-MS), proton-transfer-reaction mass spectrometry (PTR-MS), selected-ion flow-tube mass spectrometry (SIFT-MS), and others are well-known conventional techniques utilized for VOC detection. However, recent advancements in sensing devices based on optical, electrochemical, and chemoresistive materials have shown significant potential for replacing these conventional techniques without compromising accuracy and specificity. This chapter provides a basic understanding of VOCs and highlights the development of advanced vs conventional detection technologies.