ELECTROCHEMICAL BIOSENSOR DEVELOPMENT SCREEN PRINTED CARBON ELECTRODE (SPCE) BASED ON GRAPHENE OXIDE AND GOLD NANOPARTICLE (GO/AUNP) NANOCOMPOSITE FOR DOPAMINE DETECTION

• Main Author: Widya Hemasita, Andjani
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/71559
• Institution: Institut Teknologi Bandung

Dopamine (DA) is one of the neurotransmitters in the mammalian central nervous system that plays an important role in kidney function, hormonal and cardiovascular systems. The normal value of DA concentration in blood is 0-0.3 nM and in urine is 0.3-3 ?M. The development of sensors for easy, precise and selective measurement of dopamine can make a major contribution to disease diagnosis. Nanomaterial-based electrode modification in electrochemical biosensors has been widely developed and studied due to several significant results, such as high redox catalytic ability, electrochemical signal enhancement, small volume size, high and stable chemical properties, superior electron transfer ability, surface area and also good biocompatibility. In this study, a Screen Printed Carbon Electrode (SPCE) electrochemical biosensor based on graphene oxide and gold nanoparticles (GO/AuNP) was developed to detect dopamine. GO/AuNP was synthesized using the green synthesis method with clove oil as a reducing agent. Nanomaterials were characterized by Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy, X-Ray Diffraction, and UV-Vis. The drop-casting method was used to modify the carbon working electrode by taking into account several optimization parameters, such as the ratio between nanomaterials and nafion and concentration of deposition solutions. Meanwhile, the electrochemical performance of nanomaterials and dopamine oxidation were analyzed using cyclic voltammetry and differential pulse voltammetry. The results showed that the sensor has a good electrocatalytic response supporting good sensitivity for DA which has a limit of detection (LOD) of 7.5 nM; limit of quantification (LOQ) of 22.8 nM; and a linear range from 0.1 - 50 ?M with an R2 value of 0.957.