Capacitor and analysing device

A capacitor comprising:

• a first electrode;
• a second electrode, wherein a first surface of the first electrode faces a second surface of the second electrode;
• a gel structure made of a hydrogel containing a reactant that is disposed between the first and second electrodes, wherein the gel structure is configured to react with a target substance which is a target to generate a gas;
• a first insulating layer covering the first surface of the first electrode;
• and
• a second insulating layer covering the second surface of the second electrode.

An analysis device comprising:

• a capacitor comprising:
• a first electrode;
• a second electrode, wherein a first surface of the first electrode faces a second surface of the second electrode;
• a gel structure made of a hydrogel containing a reactant that is disposed between the first and second electrodes, wherein the gel structure is configured to react with a target substance which is a target to generate a gas;
• a first insulating layer covering the first surface of the first electrode;
• and
• a second insulating layer covering the second surface of the second electrode,
• wherein the analysis device is configured to analyze the target substance to estimate a concentration of the target substance.