Nanoscience as a whole has many potential applications in the defense and military sector- including chemical detection, decontamination, and forensics. Some nanosensors in development for defense applications include nanosensors for the detection of explosives or toxic gases. Such nanosensors work on the principle that gas molecules can be distinguished based on their mass using, for example, piezoelectric sensors. If a gas molecule is adsorbed at the surface of the detector, the resonance frequency of the crystal changes and this can be measured as a change in electrical properties. In addition, field effect transistors, used as potentiometers, can detect toxic gases if their gate is made sensitive to them.