ELECTROCHEMICAL BIOSENSOR USING RECOMBINANT PROTEIN FOR COVID-19 DETECTION

• Main Author: Baleno Rama, Mahendra
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/58388
• Institution: Institut Teknologi Bandung

World Health Organization (WHO) has declared coronavirus disease 2019 (COVID-19) as a pandemic because of its rapid spread throughout the world. Various efforts were made to suppress the spread of the virus by conducting tests to prevent transmission from infected individuals. Currently, reverse transcriptase polymerase chain reaction (RT-PCR) is the standard test for detecting COVID-19. However, this method is expensive and requires medical personnel, so there is a need to develop portable, accurate and affordable diagnostic tests. To answer this problem, the author developed a biosensor using electrodes modified with gold nanoparticles (AuNP). This study used single-chain fragment variable (scFv) as a bioreceptor immobilized on a AUNP-modified screen-printed carbon electrode. scFv has the advantage of having the same specificity as intact antibody despite its smaller size. The performance of the biosensor was evaluated by measuring cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) in ferrocyanide solution as a redox probe. AuNP plays an important role in increasing the conductivity of the electrode. CV measurements on AuNP-modified electrodes showed a significant increase in peak oxidation current. Meanwhile, the charge transfer resistance (Rct) decreased significantly in the EIS measurement. The biosensor was able to detect the receptor-binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition, the biosensor showed good selectivity when it is tested with infectious bronchitis virus (IBV) because there was no change in Rct.