Sensitivitas Elektroda Termodifikasi Kitosan/Grafena Oksida Tereduksi/Mangan Dioksida dalam Mendeteksi Kolesterol

Abstract

In this research, chitosan/reduced graphene oxide (rGO)/manganese dioxide (MnO2) modified electrodes have been successful in detecting cholesterol using the cyclic voltammetric method. The addition of manganese dioxide is considered to improve the performance of the electrode. Chitosan/rGO/MnO2 electrodes were fabricated using the electrodeposition method with a volume ratio of 2:1:1 using chitosan 1.5%, rGO 250 mg/L, and various concentrations of MnO2 100, 200, 300, 400, 500 and 600 mg/L. Analysis of the modified electrode surface was carried out using the Fourier Transform Infra-Red (FT-IR) and Scanning Electron Microscopy (SEM) methods. Testing the sensing properties of the chitosan/rGO/MnO2 electrode was carried out by cyclic voltammetry using the parameter voltage range of -1V to 1V and a scan rate of 100 mV/s. Tests were carried out using various concentrations of cholesterol solutions of 50, 100, 150, 200, 250 and 300 mg/L and blood serum dissolved in phosphate buffer solution. The results of the test showed that the chitosan/rGO/MnO2 electrode with a concentration of 500 mg/L MnO2 was the electrode with the best performance. The detection limit (LoD) and quantity limit (LoQ) for cholesterol detection were 0.26 μM and 0.87 μM. In the real sample test, the modified electrode is also considered capable of detecting cholesterol in blood serum, so that the chitosan/rGO/MnO2 electrode can then be applied as a basic material for sensors in detecting cholesterol.