ZnO and GO coated plastic optical fiber for low concentration of ethanol detection in beer

Ethanol is widely used in food industry, pharmaceutical industry, cosmetic and fragrance industry. This paper reports on the fabrication of ethanol sensor based on ZnO and GO coated plastic optical fiber (POF). ZnO and GO were synthesized by using simple and low-temperature Hydrothermal Method and Modified Humm ers' method, respectively. ZnO shows a hexagonal wurtzite structure based on XRD spectra, meanwhile nanorods shape is observed by using FESEM. This sensor operates based on evanescent wave absorbance principle. The cladding of the fiber is removed by using diluted acetone and sandpaper. The performance of ZnO and GO coated POF towards 0.5% to 3.5% of ethanol were analyzed and compared with uncoated POF. GO coated POF exhibit the highest sensitivity which is 0.2349 a.u/% compared to POF coated with ZnO with a value of 0.0697 a.u/%. The limit of detection of GO coated POF is 1.29% with slope linearity of 89%. Thus, GO coated POF had been selected for the detection of real Beer sample.