Ammonia optical fiber sensor based on self-assembled zirconia thin films

In order to fabricate ammonia sensors, thin films of zirconia (ZrO2) nanoclusters and poly(sodium-4-styrenesulfonate) salt have been deposited on the cleaved ends of standard communications optical fibers using the electrostatic self-assembly method. These sensors can operate at room conditions, with no need of heaters, and have shown a high selectivity to ammonia with negligible cross-sensitivity to humidity and temperature. In addition, these sensors were submitted to the presence of volatile organic compounds such as acetone, ethanol and dichloromethane, showing insignificant changes on the optical response.