Preparation and application of fiber-optic sensors based on layer-by-layer self-assembly multilayers

During last several decades, optical fiber has been applied in many disciplines and areas. Among its kinds of applications, optical fiber sensors have become an interesting research project due to the advantages of optical fiber, such as immunity to electromagnetic interferences, capability of remote measurements, multiplexed detection, small size and low weight and so on. Optical fiber has been applied in fiber-optic sensors based on polyelectrolyte layer-by-layer (LbL) self-assembly multilayers have become into a hot research field since it was reported in 2000. It has widely application in measuring trace substances. In this paper, layer-by-layer selfassembly polyelectrolytes on the surface of optical fibers as well as test of fiber-optic sensors are introduced. The fiber-optic structures, assembly materials, detection principle and performance of different fiber-optic sensors based on multilayers nanocoating are also summarized. Particularly, the preparation, test and application of fiber-optic pH sensors, fiber-optic humidity sensors, fiber-optic gas sensors and fiber-optic biosensors in last decade are reviewed. The outlook of fiber-optic sensors based on LbL polyelectrolyte self-assembly multilayers is suggested.