Device and method for detecting a substance

A device (1) for detecting at least one substance of a fluid (9), having at least one piezo acoustic resonator (2) comprising

• at least one piezoelectric layer (4),
• an electrode (5, 6) disposed on the piezoelectric layer (4)
• at least one further electrode (6, 5) disposed on the piezoelectric layer (4), and
• a surface section (8) for sorption of the substance of the fluid (9),
• wherein the piezoelectric layer (4), the electrodes (5, 6) and the surface section (8) are arranged with respect to one another in such a way that an electrical actuation of the electrodes (5, 6) leads to an oscillation of the resonator (2) at a resonance frequency and the resonance frequency is dependent on an amount of the substance sorbed on the surface section (8),
• characterized in that
• a layer thickness (7) of the piezoelectric layer (4) is chosen from the range of 0.1 μm inclusive to 20 μm inclusive and
• the resonance frequency of the oscillation is chosen from the range of 500 MHz inclusive to 10 GHz inclusive.