Novel examples of optical sensors for micro-respirometry

The system enables quantification of total viable counts of aerobic bacteria and is validated using multiple clinically relevant species. Its performance was shown to be comparable to commercial systems while offering advantages in scalability, simplicity, and applicability to solid samples. Chapter 4 builds on this sensing system through integration of the O₂ indicator into a commercial occlusive wound dressing, creating a non-invasive smart wound monitoring system.

Using agar-based and porcine skin wound models, the system successfully identifies critical bacterial colonisation thresholds associated with infection highlighting its potential as an early warning indicator of infection. <br><br>Chapters 5 and 6 describe the development of simple, low-cost colourimetric NH₃ indicators for monitoring bacterial growth and ureolytic activity in solid wound models and liquid cultures. Quantitative analysis is achieved using digital colour analysis, under aerobic and anaerobic conditions.

Overall, this work demonstrates the versatility of optical gas-sensing indicators for real-time, non-invasive monitoring of microbial growth, with applications in diagnostics, environmental monitoring, and smart wound care.