FABRICATION AND MODIFICATION SCREEN PRINTED CARBON ELECTRODE FOR NON-ENZYMETIC DETECTION OF UREA

• Main Author: Hasanah, Nadia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50343
• Institution: Institut Teknologi Bandung

Urea is one of the organic compounds produced by metabolism that can be used as an indicator of a disease. One method of detecting urea is using the urase enzyme. This method is quite complicated because the reaction is dependable on pH and temperature. An alternative method for non-enzymatic detection is needed, which uses Screen Printed Carbon Electrode (SPCE). SPCE is an electrochemical sensor that has the advantages of being cheap, simple, and semiportable. Despite has some disadvantages including less sensitivity and a weak response to analytes. It’s necessary to modify the surface of the working electrode to increase the SPCE performance. In this final project, polyaniline and Fe3O4-GO were added to surface of the working electrode as supporting material. Polyaniline was chosen because it’s high conductivity compared to other polymers wherese Fe3O4-GO was chosen because it’s unique chemical structure. After adding the supporting material, testing is carried out to detect urea. The test results show that the composite mixture of two materials exhibit 7 greater current response than using pure polyaniline and pure Fe3O4-GO. It is known that SPCE coated with Fe3O4-GO polyaniline has a sensitivity of 0.0655 A/M cm2 which shows a decreased response with increasing urea concentration (range 2-14 mM), with Limit of Quantification 1.73 mM and Limit of Detection 0.52 mM. However, SPCE/Fe3O4-GO polyaniline still cannot be used as specific sensor for urea because its respond to dopamine which has the same working potential as urea. SPCE can only be used once or if it is used repeatedly, there is a decrease in sensitivity by 5-10%. Based on test, SPCE performance decreased by 1-7% per cycle.