Sensitivitas Elektroda Termodifikasi Kitosan/Grafena Oksida Tereduksi/Fe3O4 dalam Mendeteksi Kolesterol

Abstract

In this research, the chitosan/rGO/Fe3O4 modified electrode has been successfully carried out in detecting cholesterol using the cyclic voltammetry method. The chitosan/rGO/Fe3O4 electrode was fabricated using the electrodeposition method using a ratio of 2:1:1 using 1.5% chitosan, rGO variations of 50, 100, 150 and 200 ppm, and Fe3O4 variations of 75, 95, 105, and 120 ppm. Surface analysis of the modified electrode was carried out using the Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscopy (SEM) methods. Testing the sensing properties of the chitosan/rGO/ Fe3O4 electrode was carried out using the cyclic voltammetry method using voltage range parameters of -1V to +1V and a Scan Rate of 100mV/s. Testing was carried out with variations of cholesterol of 100, 150, 200, 250, and 300 ppm and blood serum dissolved in phosphate buffer solution. The results of the test produced a chitosan/rGO/ Fe3O4 electrode with an rGO concentration of 100 ppm and an Fe3O4 concentration of 95 ppm which is an electrode with good performance. The limit of detection (LoD) and Limit of quantity (LoQ) in cholesterol detection were 0,23 ppm and 0,79 ppm . In real sample testing, the modified electrode was also considered capable of detecting cholesterol in blood serum, so that the chitosan/rGO/Fe3O4 electrode can then be applied as a basic sensor material in detecting cholesterol.