CARBON PASTE ELEKTRODE MODIFIED WITH MOLECULARLY IMPRINTED POLY (METHYL ORANGE) FOR VOLTAMMETRIC DETERMINATION OF DOPAMINE

• Main Author: KOMALA EKA SARI (NIM: 20514038), NUR
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23579
• Institution: Institut Teknologi Bandung

Dopamine (DA) is a neurotransmitter made along synthesis of norephinephrin which is important for nervous system. High concentration of dopamine may cause autism, schizofrenia and paranoia. Conversely, low concentration is related to Parkinson disease. Normal concentration of dopamine in human is around 10 7 to 10 3 mol/L. Analytical methods usually used to determine dopamine in body fluids, such as UV-Vis spectrometry and High Performance Liquid Chromatography (HPLC) have disadvantages such as complicated preparation procedure, long analysis time, and expensive. On the other hand, voltammetry method is interfered by high concentration of ascorbic acid and uric acid. Therefore, to resolve this problem, development of selective and sensitive sensors are needed to do so. In this study, molecularly imprinted polymer (MIP) modified carbon paste electrode CPE) is developed as working electrode in voltammetric determination of dopamine. The surface of CPE was modified with molecularly imprinted poly (methyl orange) through electropolymerisation process in phosfat buffer solution (PBS) pH 7 containing methyl orange 0.5 mM and dopamine 0.1 mM. Electropolymerisation was conducted using 10 cycle of cyclic voltammetry in potential range of - 600 mV - 1400 mV with scan rate of 100 mV/s. The MIP was formed by removing dopamine using 19 cycle of cyclic voltammetry in the same potential range from PBS pH 7 solution. Differential pulse voltammetry (DPV) technique was used for dopamine determination. Repeated measurement of dopamine 0,1 mM resulted in RSD of 4,93% (n=28). Reproducibility of producing MIP modified CPE was very good. Determination of dopamine in spiked blood plasma using DPV method resulted in percent recovery in the range of 98.5% - 103.0%.