Various embodiments may relate a chemical sensor. The chemical sensor may include a substrate including a first sealed (or isolated) cavity and a second sealed (or isolated) cavity separate from the first sealed (or isolated) cavity. The chemical sensor may also include an emitter in the first sealed (or isolated) cavity, the emitter configured to emit infrared light. The chemical sensor may further include a detector in the second sealed (or isolated) cavity. The chemical sensor may also include a waveguide configured to carry the infrared light from the emitter to the detector. The waveguide may include a sensing portion configured such that a property of the infrared light carried through the sensing portion changes in response to a chemical entity in contact with the sensing portion. The detector may be configured to detect the change in the property (of the infrared light).