Optical Fiber Sensor With ZnO Hierarchical Nano-Structures Grown on Electrospun ZnO Mat Base on the Sensor for Trace Level Detection of Volatile Amines

This article demonstrates an optical fiber sensor probe coated with hierarchical nanostructures of zinc oxide (ZnO) for trace level detection of volatile amines. The nanostructure is grown by hydrothermal process on a multimode optical fiber probe coated with ZnO nanofibrous mat prepared by electrospinning technique. The high surface area of the hierarchical structures facilitated diffusion of amines, which, on interaction with ZnO surface, changes the effective refractive index of the optical fiber probe. The modulation of the transmitted intensity through the optical sensor probe in presence of the target analyte is monitored for sensing the amine. An increase in absorbance is observed in proportion to amine concentrations with the emergence of a broad peak at around 500 nm. The sensor is able to detect as low as 25 ppb of different volatile amines such as ammonia, triethylamine, aniline, and ethylenediamine with responses of 1%, 0.65%, 0.75%, and 0.5%, respectively. The sensor is further demonstrated for detection of volatile amines released during protein degradation in salmon fish to show its usability for real time applications.