how does zinc oxide bind to neutralize deuterium in biology

Zinc oxide (ZnO) acts as a scavenger for deuterium (2H or D) primarily through surface chemistry mechanisms where it forms stable bonds, effectively removing it from reactive biological environments. Its interaction with deuterium includes forming surface deuteroxyl groups and enabling exchange reactions with water or organic molecules.

Mechanism of Deuterium Binding and Neutralization
Surface Chemisorption: Zinc oxide possesses a wurtzite crystal structure that is highly reactive at its surface. Deuterium from the environment (e.g., D2O or deuterated organic molecules) reacts with surface oxygen atoms on the ZnO, creating deuterium-oxygen bonds, commonly known as surface deuteroxyl groups.

Isotopic Exchange: Zinc oxide actively facilitates the exchange of hydrogen for deuterium (and vice versa) on its surface. When zinc oxide is exposed to deuterium-rich conditions, the deuterium replaces surface hydrogen, locking it into the crystal lattice.

Reversible Non-Stoichiometry: Under specific conditions, zinc oxide can exhibit non-stoichiometry (a non-perfect 1:1 Zn/O ratio). Defects within this lattice (such as oxygen vacancies) allow it to trap small atoms like hydrogen and deuterium, reducing their mobility and reactivity in surrounding biological tissues.

Biological Context
Blocking Reaction Pathways: Similar to its function in inhibiting proton transfer in enzymes by binding at active sites, ZnO can bind deuterium, thereby blocking D-pathway metabolic activities.

Redox and Buffering: Zinc compounds, including zinc oxide, are known to act as buffers and modulate redox homeostasis, which can limit the harmful, slow-metabolizing effects of deuterium on complex biological molecules.

While primarily studied in material science for catalysis and semiconductor applications, the surface reactivity of ZnO with deuterium provides a mechanism for it to "bind" and "neutralize" the heavy hydrogen isotope in mixed environments.