  Molecular adsorption is pivotal in device fabrication and material synthesis
for quantum technology. However, elucidating the behavior of physisorption
poses technical challenges. Here graphene with ultrahigh sensitivity was
utilized to detect ozone adsorption at cryogenic temperatures. Significant hole
doping observed in graphene indicates a strong interaction between ozone and
graphene. Interestingly, the adsorption exhibits asymmetry with positive and
negative gate voltages. The strong affinity of ozone provides a tool to
modulate materials and devices, while the gate tunability of adsorption offers
new insights into construction and manipulation of oxide quantum materials.
