In-situ biological ozone detection by measuring electrochemical impedances of plant tissues.

This work demonstrates the biological detection of low-level by measuring electrochemical impedances of stem tissues in tobacco and tomato plants, both indoor and outdoor. Ozone concentrations as low as 30 above ambient levels were detected via physiological responses, enabling the use of phytosensors as biodetectors of environmental pollutants. exposure affects stomatal regulation that in turn alters the hydrodynamics of fluid transport system in plants. The measurement results indicate a reaction of hydrodynamic system to changes in concentration with a delay of 10-20 min between the onset of exposure and biological response. The probability of false-negative responses from a plant is 0.15 ± 0.06. Pooling data from at least three plants allows for 92% confidence in detecting excess . Measurements on days with low and high ozone levels of 80 to 130 result in a 2.33-fold difference in sensor readings at these levels, underscoring the sensitivity of the method. Statistical robustness is supported by 948 plant-sensor measurements with 9 plants over 51 days, totaling 107 samples via automated monitoring. Long-term field tests demonstrate the reliability of electrochemical methods. This approach has applications in environmental monitoring, biological pollution detection and biosensing.