Low-Cost High-Sensitive Plastic Optical Fiber-Based Sensor for Detection of CO(NH2)2 Urea

Abstract

In this research, a urea level sensor based on plastic optical fiber was made using the macro bending method and two kinds of configurations. The sensor is made with a gamma and band configuration with a variety of cladding, no cladding, and imperfection and immersed in the urine sample which has different urea. This is aimed at determining the optimal sensor as a urea level sensor. The object measured was a urine sample with different urea concentrations ranging from 336.1 mg/dL to 1384.3 mg/dL, with the same volume for each concentration in the container or sample holder. The light from LED is transmitted through a plastic optical fiber, received by the phototransistor, then amplified by the differential amplifier, and converted by the microcontroller to voltage as the final results on the computer. Changes in urea levels result in changes in the refractive index around the sensor. The results showed that the more imperfection given to the plastic optical fiber sensor with gamma and band configuration, the better the range, sensitivity, and resolution. The best measurements were obtained in the band configuration with PANI-ZnO coating using six imperfections with the range value of 0.514 volts, the sensitivity value of 0.367 mvolt/mg dL-1, and the resolution value of 2.724 mg/dL. The sensor is suitable for urea levels in medical, agricultural, or industrial applications with the advantages of high sensitivity, low cost, and ease of operation.