SYNTHESIS OF METAL OXIDE NANOPARTICLE (FE3O4) - GRAPHENE OXIDE AS MATERIAL OF ACTIVE ELECTROCHEMICAL SENSORS FOR DOPAMINE DETECTION

• Main Author: Arya Attyla Kepakisan, Komang
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50643
• Institution: Institut Teknologi Bandung

Dopamine concentration abnormalities in the body, can cause various kinds of disorders and diseases such as Parkinson's, Tourette's syndrome, impaired concentration or hyperactivity depression, anxiety disorders, insomnia, delusional, digestive problems, and various disorders in other physiological systems. Therefore detection of dopamine levels as a method of early diagnosis on a micro-basis is very important. In this study graphene oxide (GO) was deposited with Fe3O4 as a supporting material to improve the electrochemical performance of the sensor in the detection of dopamine. The performance of sensors which surface has been modified by FeGO is carried out by the Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) methods. The results of testing with CV on the solution [Fe(CN)6] showed that a modification with GO gave the maximum effective surface area value of 0.0127 cm2 which proves that GO can increase the effective area and conductivity of the sensor. Then the comparison of dopamine in different consentration between GCE without modification with modification indicate that the modified GCE shows the ability to detect dopamine with the highest peak current value (Ip) owned by FeGO of 113.09 ?A / Cm2 for anodic reaction and 105.12 ?A / Cm2 for cathodic reactions. A linear relationship is seen in the CV results between peak oxidation current densities and reductions in increasing dopamine concentrations. DPV testing shows that FeGO has a linear range at a concentration of 1 - 20 ?M with a sensitivity of 5 ?A ?M-1 cm-2 , a detection limit of 0.029 ?M, a quantification limit of 0.097 ?M, with a relative measurement error of 6.052%. FeGO shows good selectivity where the peak current is separated by 0.245 V with ascorbic acid which is the closest interference compound. FeGO testing after being stored for a certain period of time shows a decrease in the peak value of the current observed with a linear relationship equation.