Prompt: 1. Tunneling nanoreactor 2. Engineered nanopipette technology 3. Cyt c encapsulated ZIF-8 nanoparticles 4. Nanoconfined reaction tunnel 5. Single living cell 6. Subcellular H2O2 7. Ionic current signal 8. ZIF-8 triggered enhancement 9. Cyt c enzyme activity 10. H2O2 elimination 11. Molecular dynamics simulations 12. Stability of Cyt c 13. Activity of Cyt c 14. Encapsulation in ZIF-8