Zarin, A. S.A. S.ZarinChakraborty, Arup LalArup LalChakraborty2025-08-302025-08-302017-01-04[9781509039210]10.1109/WRAP.2015.78059762-s2.0-85015836663https://d8.irins.org/handle/IITG2025/22551This paper reports the use of tunable diode laser absorption spectroscopy to make absolute measurement of the concentration of carbon dioxide (CO<inf>2</inf>) emitted by E. coli and lactic acid bacteria (LAB) at different stages of their growth cycle. The emission wavelength of a 2004 nm vertical cavity surface emitting laser diode is scanned across the R16 rotation-vibration line of CO<inf>2</inf> at 2003.5 nm (4991.259 cm^-1) by current tuning. Direct detection is performed to recover the lineshape accurately and the absolute values of the CO<inf>2</inf> concentration are extracted over the growth cycle of the bacteria. The time-varying CO<inf>2</inf> emissions agree well with theoretical models available in the literature. The calibration-free nature of these measurements is particularly important for such experiments.falsebiomarkers | Bioreactors | E. coli | TDLAS | VCSELConference Paper4 January 201717805976cpConference Proceeding0