A probe for underground sensing of materials of interest, for example chemicals such as explosives, includes a probe body that is capable of being inserted into the ground, and one or more sensors that are able to sense one or more materials in the vicinity of at least a portion of the probe body. The sensor(s) may include a light source that directs light to the vicinity of the portion of the probe body, and a light detector, such as a photosensor or spectrometer, that detects reflected light from the material around the probe body. The reflected light may be analyzed to determine the presence of one or more materials of interest, such as chemicals used in explosive devices. The probe may be part of a vehicle used to detect and neutralize buried explosive devices, with the probe for example being on an articulable arm of the vehicle.