Comparative study of chemical probes for ozone detection

Plasma composition is typically studied by absorption and emission spectroscopy, mass spectrometry and computational studies. While these techniques provide valuable information about the chemical species in the gas phase, in many applications it is desirable to have a direct measurement of the dose of chemical species delivered to a particular target. For this purpose, chemical probes are particularly interesting as they can provide an inexpensive means for determining the dose of a particular compound. A number of chemical probes have recently been used by the plasma community, particularly those working in plasma medicine and with plasmas interacting with liquids. Generally, however, these probes were not initially intended for use in plasma environments and therefore, it is important to assess their suitability and identify any selectivity issue that could affect the correct interpretation of the measurements. Here, we report on a comparative study of three chemical probes aimed at the quantitative detection of ozone (Table 1): Indigo Carmine and two DCF-derived fluorescent probes.