Table 1.

The immobilization methods for enzyme-based electrochemical gas sensors.

Gases	Enzyme	Immobilization Methods	Ref.
Ethanol	Alcohol oxidase	Entrapment	[25]
Carbon dioxide	Carbonic anhydrase	Entrapment	[33]
Lactic acid	Lactate oxidase	Physical adsorption	[34]
Methanol	Alcohol oxidase	Crosslinking	[35]
Choline	Choline oxidase	Entrapment	[36]
Formaldehyde	Formaldehyde dehydrogenase	Covalent Coupling	[37]