| Title: | Absolute noninvasive measurement of CO(2) mole fraction emitted by E. coli and S. aureus using calibration-free 2f WMS applied to a 2004 nm VCSEL |
| Author(s): | Zarin AS; Chakraborty AL; Upadhyay A; |
| ISSN/ISBN: | 1539-4794 (Electronic) 0146-9592 (Linking) |
| Abstract: | "We report the first demonstration, to the best of our knowledge, of accurate real-time noninvasive measurement of the absolute cumulative mole fraction of metabolic carbon dioxide emitted by Escherichia coli and Staphylococcus aureus over a period of several hours of their life cycles using a recently developed calibration-free wavelength modulation spectroscopy technique. A 1 mW vertical-cavity surface-emitting laser is used to interrogate a single rotational vibrational absorption line of carbon dioxide at 2003.5 nm. The measurements are immune to laser intensity fluctuations and variable optical coupling that is inevitable in such free-space coupled experiments that run over 10-18 h. The cumulative carbon dioxide mole fraction follows the characteristic modified Gompertz model that is typical of bacterial growth in batch cultures. The characteristic growth parameters are extracted from this curve. The technique can be readily extended to study multiple volatile organic compounds that bacteria are known to emit" |
| Notes: | "PubMed-not-MEDLINEZarin, A S Chakraborty, Arup Lal Upadhyay, Abhishek eng 2017/06/02 Opt Lett. 2017 Jun 1; 42(11):2138-2141. doi: 10.1364/ol.42.002138" |
