| dc.description.abstract | Chitosan (CS)/reduced graphene oxide (rGO) modified platinum electrode has been
successfully tested using cyclic voltammetry (CV) method to detect urea fertilizer
concentration. Chitosan-reduced graphene oxide (rGO) was fabricated using the drop
casting method, in which the mixed solution was deposited onto the surface of the
platinum substrate. Both solutions were prepared using a volume ratio of 1:1, where
the mixed solution consisted of 1.5% chitosan solution and rGO solution with
various concentrations of 200, 250, 300, 350, and 400 ppm. Furthermore, for the test
sample solution of urea fertilizer, it was made with various concentrations, namely
50, 100, 150, 200, and 250 ppm. The chitosan-rGO films were characterized using
Fourier Transform Infra-Red (FTIR) and X-Ray Diffraction (XRD) methods. Based
on the results of FTIR and XRD analysis, it showed that rGO interacted physically
with CS and has 22θ at 9.8°; 18.59°; 22.57°, dan 37,14° with d-spacing 9,9 Å. Based
on the test results using the cyclic voltammetry (CV) method, the CS/rGO electrode
had optimum results at a concentration of 250 ppm rGO in a PBS pH 7 electrolyte
solution and optimum detection of 150 ppm urea fertilizer with a potential value of -
0.29626 V. The optimum results chitosan-rGO modified electrodes in detecting urea
fertilizer was strengthened by the presence of good linearity at a regression value of
0.6933 and a limit of detection of 105 ppm. It indicates that chitosan-rGO modified
electrodes has moderate sensitivity for the detection of urea fertilizer and can be
applied as a sensor-based material, especially for detecting of fertilizer
concentrations. | en_US |
