Sampling and emerging spectroscopic techniques for exhaled breath analysis: Analytical advances and future directions

Exhaled breath aerosols (EBAs) play a vital role in the transmission of respiratory and infectious diseases, raising health concerns regarding airborne pathogen spread, allergies, and pollution exposure. Effective monitoring and analysis of EBAs, including volatile organic compounds (VOCs) and exhaled breath condensates (EBCs), is essential for enhancing infection control and individualized treatment. This review article focuses on the importance of emerging Fourier-transform infrared (FTIR) spectroscopy and combined techniques such as mass spectroscopy, Raman, polymerase chain reaction, and related techniques in the detection and characterization of EBAs, particularly its capacity to identify essential biological markers including proteins and lipids in the context of personalized healthcare. We also examine current advances in EBA sampling techniques, including impactors, filtration, and cyclone samplers, as well as issues including standardization and environmental interference in breath analysis. The combination of FTIR-based analytical methods and optimized EBA sampling methodologies represents a viable strategy for increasing bioaerosol detection, real-time disease surveillance, and air quality monitoring in clinical and personalized health settings.