DEVELOPMENT OF ELECTROCHEMICAL BIOSENSORS BASED ON SCREEN-PRINTED CARBON ELECTRODE MODIFIED WITH CITRIC ACID MODULATOR INDUCED-FE-BDC METAL-ORGANIC FRAMEWORK FOR DETECTION OF HEPATITIS C

• Main Author: Taufik Ulhakim, Muhamad
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/68021
• Institution: Institut Teknologi Bandung

Hepatitis C is an infectious disease that attacks the liver. Some people think that hepatitis C is not a dangerous disease because the transmission process only occurs through the parenteral route or contact with infected blood, for example sexual activities, sharing needles, or being transmitted from mother to child through the birth process. In fact, hepatitis C needs special attention because it can develop into serious diseases such as chronic hepatitis, cirrhosis, or carcinoma hepatocellular, even in acute conditions it can only be treated through liver transplantation. In addition, there is no effective vaccine of hepatitis C to suppress the rate of transmission. As a solution to these problems, the World Health Organization (WHO) launched an early detection program so that hepatitis C infection can be detected as early as possible and the possibility of developing serious can be avoided. The method of early detection of hepatitis C that has been widely developed is an immunosensor-based electrochemical biosensor, namely by detecting the presence of pathogens (hepatitis C virus) in the blood. However, along with the development of science, this method requires a development so that the detection process can be carried out easily and effectively, as well as low-cost (does not require high costs). Therefore, in this study, the development of an immunosensor-based electrochemical biosensor with a focus on material modification was carried out through a screen-printed carbon electrode (SPCE) approach. The use of SPCE is based on several advantages, one of which is the use of relatively little electrolyte so that it can reduce costs in the analysis process. In this study, material modification was carried out by adding a citric acid modulator to the metal-organic framework ferrite benzenedicarboxylic acid (MOF Fe-BDC-AS). The added citric acid modulator was varied, consisting of 0.1 mmol, 0.3 mmol, and 0.5 mmol with the aim of obtaining the MOF Fe-BDC-AS which had the most optimum conditions, so as to provide good electrochemical capabilities. The most optimum MOF Fe-BDC-AS was then applied as an electrochemical biosensor to detect hepatitis C using the SPCE approach by immobilizing the working electrode. Furthermore, the electrochemical capability of the MOF Fe-BDC-AS was evaluated through several tests, such as the cyclic voltammetry (CV) test which aims to determine the optimum conditions, the differential pulse voltammetry (DPV) test which aims to determine the most optimum capability of the MOF Fe-BDC-AS in detect hepatitis C, as well as electrochemical impedance spectroscopy (EIS) testing as supporting data or validation process for CV and DPV test results. The results of the evaluation showed that the optimum condition of the MOF Fe-BDC-AS was achieved by adding an AS modulator at a concentration of 0.3 mmol (MOF Fe-BDC-AS3). These results were confirmed by CV testing which informed that the MOF Fe-BDC-AS3 produced the largest reduction and oxidation current values compared to other variations, around 28.00 ?A and 23.06 ?A, respectively. Therefore, in this study, the hepatitis C detection process was carried out by modifying the SPCE working electrode using the MOF Fe-BDC-AS3. Furthermore, the hepatitis C detection process was carried out using DPV testing in a linear range of target concentration (HCV-Ag) of 1000 ng/ml to 0.5 ng/ml. The test informs that the MOF Fe-BDC-AS3 has the lowest detection limit or limit of detection (LoD) of 0.75 ng/ml. DPV testing was also carried out to determine the electrochemical performance of the MOF Fe-BDC-AS3 which included stability, reproducibility, sensitivity, and reusability. The test results inform that the MOF Fe-BDC-AS3 has good stability and reproducibility in detecting hepatitis C. This is evidenced by the test results which give an RSD value of 4.08% for stability and 2.30% for reproducibility. In addition, the selectivity level of the MOF Fe-BDC-AS3 was tested against four types of hepatitis viruses consisting of hepatitis A, B, C, and D. The test results showed that the MOF Fe-BDC-AS3 was able to recognize the hepatitis C virus quite well, as seen of the resulting current delta response of 15.90 ?A. This value is greater than 71% of hepatitis A, 66% of hepatitis B, and 44% of hepatitis D. However, the MOF Fe-BDC-AS3 as an electrochemical biosensor has poor reusability, as seen from the DPV test response which decreases with time. repetition of tests performed. This is made possible by the use of SPCE electrodes which are only optimal for single use. Finally, the EIS test carried out provides validation results that are in accordance with the results of the CV and DPV testing. Based on these results, the MOF Fe-BDC-AS3 as an electrochemical biosensor meets the criteria to be used as an innovation in the hepatitis C detection process, especially in Indonesia.