Sensitivitas Elektroda Berbasis Grafena Oksida Tereduksi/Kitosan/Titanium Dioksida Dalam Mendeteksi Kolesterol Dengan Siklik Voltametri

Abstract

In this research, chitosan/reduced graphene oxide(rGO)/titanium dioxide (TiO2) modified electrodes have been successful in detecting cholesterol using the cyclic voltammetric method. The addition of titanium dioxide is considered to improve the performance of the electrode. Chitosan/rGO/TiO2 electrodes were fabricated using the electrodeposition method with a volume ratio 1:1:1 using chitosan 1,5% rGO 250 mg/L,and various concentrations of TiO2 200,400,600,800 and 1000 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/TiO2 electrode was carried out by cyclic voltammetry using the parameter voltage rang of -1V to 1V and a scan rate of 75 mV/S. Tests were carried out using various consentrations of cholesterol solutions of 100,150,200,250 and 300 mg/L and blood serum dissolved in phospate buffer solution. The results of the test showed that the chitosan/rGO/TiO2 electrode with a concentration of 800 mg/L TiO2 was the electrode with the best performance. The detection limit (LoD) and quantity limit (LoQ) for cholesterol detection were 46 µM and 155 µM. In the real sample test, the modified electrode is also considered capable of detecting cholesterol in blood serum, so that the chitosan/rGO/TiO2 electrode can then be applied as a basic material for sensors in detecting cholesterol.