O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry
The popular method of micro-respirometry (μR) for measuring total viable (aerobic) count (TVC) utilises luminescence-based O<sub>2</sub> sensors that are difficult to fabricate and therefore expensive. A simple method is described for making inexpensive, ink-based potential substitutes t...
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MDPI AG
2024-09-01
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| author | Sean Cross Dilidaer Yusufu Christopher O’Rourke Andrew Mills |
| author_facet | Sean Cross Dilidaer Yusufu Christopher O’Rourke Andrew Mills |
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| description | The popular method of micro-respirometry (μR) for measuring total viable (aerobic) count (TVC) utilises luminescence-based O<sub>2</sub> sensors that are difficult to fabricate and therefore expensive. A simple method is described for making inexpensive, ink-based potential substitutes that utilise the same O<sub>2</sub>-sensitive dyes. The sensitivity of such inks is readily increased by using dyes with a long lifetime in the absence of O<sub>2</sub>, τ<sub>o</sub>, and/or an ink resin/polymer with a high O<sub>2</sub> permeability, P<sub>m</sub>(O<sub>2</sub>). Response modelling of the μR-based TVC system and subsequent testing using a range of O<sub>2</sub> sensors of different sensitivity show that there is little to be gained by making the O<sub>2</sub> sensor either very sensitive or insensitive, and that the best O<sub>2</sub> sensors are dyes such as Pt(II) tetraphenyltetrabenzoporphyrin (PtBP), with τ<sub>o</sub> = ca. 40–50 μs. Further work shows that a simple-to-make PtBP ink can be used as a direct replacement for the expensive O<sub>2</sub> sensor used in commercial instruments for measuring TVC based on μR. In addition, the PtBP can be replaced by an even less expensive O<sub>2</sub>-sensitive dye, Pt(II) meso-tetra(pentafluorophenyl)porphyrin (PtTFPP). The potential use of inexpensive O<sub>2</sub>-sensitive inks as an alternative to any expensive commercial counterpart based on the same O<sub>2</sub>-sensitive dye is discussed briefly. |
| format | Article |
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| publishDate | 2024-09-01 |
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| spelling | doaj-art-cadf1e38dca5485a944ffbda442986242025-08-20T01:55:28ZengMDPI AGChemosensors2227-90402024-09-0112919010.3390/chemosensors12090190O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-RespirometrySean Cross0Dilidaer Yusufu1Christopher O’Rourke2Andrew Mills3School of Chemistry and Chemical Engineering, Queens University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, UKSchool of Chemistry and Chemical Engineering, Queens University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, UKSchool of Chemistry and Chemical Engineering, Queens University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, UKSchool of Chemistry and Chemical Engineering, Queens University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, UKThe popular method of micro-respirometry (μR) for measuring total viable (aerobic) count (TVC) utilises luminescence-based O<sub>2</sub> sensors that are difficult to fabricate and therefore expensive. A simple method is described for making inexpensive, ink-based potential substitutes that utilise the same O<sub>2</sub>-sensitive dyes. The sensitivity of such inks is readily increased by using dyes with a long lifetime in the absence of O<sub>2</sub>, τ<sub>o</sub>, and/or an ink resin/polymer with a high O<sub>2</sub> permeability, P<sub>m</sub>(O<sub>2</sub>). Response modelling of the μR-based TVC system and subsequent testing using a range of O<sub>2</sub> sensors of different sensitivity show that there is little to be gained by making the O<sub>2</sub> sensor either very sensitive or insensitive, and that the best O<sub>2</sub> sensors are dyes such as Pt(II) tetraphenyltetrabenzoporphyrin (PtBP), with τ<sub>o</sub> = ca. 40–50 μs. Further work shows that a simple-to-make PtBP ink can be used as a direct replacement for the expensive O<sub>2</sub> sensor used in commercial instruments for measuring TVC based on μR. In addition, the PtBP can be replaced by an even less expensive O<sub>2</sub>-sensitive dye, Pt(II) meso-tetra(pentafluorophenyl)porphyrin (PtTFPP). The potential use of inexpensive O<sub>2</sub>-sensitive inks as an alternative to any expensive commercial counterpart based on the same O<sub>2</sub>-sensitive dye is discussed briefly.https://www.mdpi.com/2227-9040/12/9/190micro-respirometryaerobestotal viable countoxygen sensor inks |
| spellingShingle | Sean Cross Dilidaer Yusufu Christopher O’Rourke Andrew Mills O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry Chemosensors micro-respirometry aerobes total viable count oxygen sensor inks |
| title | O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry |
| title_full | O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry |
| title_fullStr | O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry |
| title_full_unstemmed | O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry |
| title_short | O<sub>2</sub>-Sensitive Inks for Measuring Total (Aerobic) Viable Count Using Micro-Respirometry |
| title_sort | o sub 2 sub sensitive inks for measuring total aerobic viable count using micro respirometry |
| topic | micro-respirometry aerobes total viable count oxygen sensor inks |
| url | https://www.mdpi.com/2227-9040/12/9/190 |
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