One approach to realize selective chemical sensors is the integration of colorimetric materials as gas sensitive substances. Color changes, due to the reaction with the target gas, can be detected optically. These kinds of sensors offer various advantages, such as fast response times and the use of simple instrumentation.
Being selective, reliable and energy-saving, the integration into different low-power applications such as fire detectors, RFID-labels or energy autarkic systems and sensor networks is possible. Therefore a low-cost and fully reversible sensor system capable to detect CO, NO2, NH3 and C2H4 at low concentrations in air was developed.