Figure 3 (IMAGE) Kanazawa University Caption (a) Explanatory schematic of the extracellular production of H<sub>2</sub>O<sub>2</sub> by NOX complex, the consequent absorption through Aquaporin channel and the reaction with intracellular peroxiredoxin. At steady-state condition, the concentration ratio of extracellular H<sub>2</sub>O<sub>2</sub> to intracellular H<sub>2</sub>O<sub>2</sub> can be estimated by the ratio of the rate constant of H<sub>2</sub>O<sub>2</sub> reduction by peroxiredoxin (kprx) to the rate constant of H<sub>2</sub>O<sub>2</sub> absorption through the plasma membrane (kabs). (b)-(c) Typical results of redox biology experiments with fitting lines from which we measured kabs and kprx, respectively. (d) Mean surface extracellular [H<sub>2</sub>O<sub>2</sub>]e and the typical maximum of [H<sub>2</sub>O<sub>2</sub>]e measured on A549 cells using the newly designed nanosensor. (e) Mean intracellular [H<sub>2</sub>O<sub>2</sub>]i and the typical maximum of [H<sub>2</sub>O<sub>2</sub>]i estimated on A549 cells according to the model reported in (a) and using the results from (b)-(d). Credit Kanazawa University Usage Restrictions The image may only be used with appropriate caption and credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.