Detection of different concentrations of uric acid using tapered silica optical sensor coated with zinc oxide (ZNO)

Abstract

The working principle of measurement of output power from silica optical sensor for the detection of different concentrations of uric acid is demonstrated. The fabricated sensors used single mode silica optical fibers (SOF) which were tapered using flame brushing technique to achieve a waist diameter of 32 µm and tapering length of 2 mm. The tapered fiber were then coated with ZnO nanostructures using sol–gel immersion method. The concentration of the uric acid is measured in volume parts per million (ppm) for a concentration change from 0 ppm to 500 ppm by tapered SOF coated with ZnO and non-coated sensors. The peak voltage increases linearly for coated and non-coated from 214 mV to 268 mV and 270 mv to 344 mV, respectively. Sensitivity was measured with 0.11 mV/ppm and 0.15 mV/ppm, respectively. In addition, the results show that the linearity of the sensors is 94.56% and 97.78%, respectively. Simple in fabrication and low in cost, this sensor can detect concentration changes of uric acid in a fast and convenient way with high stability and sensitivity. Thus, this sensor will be very promising in chemical and biomedical applications.