An Electrochemical Biosensor Based On Gold Nanoparticle-Modified Screen-Printed Carbon Electrode For The Detection Of Sars-Cov-2 Nucleocapsid Protein

Abstract

The global health landscape has been profoundly affected by the emergence and re-emergence of contagious diseases such as SARS, MERS, Ebola, Zika, and most recently, SARS-COV-2. These outbreaks highlight the urgent need for rapid, accurate, and accessible diagnostic tools to prevent widespread transmission and mortality. While electrochemical sensors have shown promise in detecting antigens of various infectious diseases, challenges such as sensitivity, selectivity, and cross-reactivity persist, leading to false positives and reduced test accuracy. To tackle this challenge, it's crucial to carefully optimize sensor design and choose the right capture agents. This research presents an enhanced screen-printed carbon electrode (SPCE) that integrates gold nanoparticles (AuNPs) and Staphylococcus protein A, employing a sandwich assay technique for detecting antigens. The signal was then measured using the amperometry technique through a reaction between conjugated HRP and luminol. Successful electrodeposition of AuNPs onto the electrode surface enhances electrochemical signal and sensor sensitivity. Nonetheless, electrochemical impedance spectroscopy (EIS) confirms successful electrode step-by-step modification. Experimental results confirm the sensor's effectiveness in detecting the SARS-COV- 2 N-protein, with a determined limit of detection (LOD) of 4.02 pg.mL-1 and a limit of quantification (LOQ) of 13.4 pg.mL-1. Moreover, the stability and specificity test has been conducted to prove the ability of the biosensor to detect SARS-COV-2 N-Protein without any cross-reactivity with other viruses for an amount of time. While the results are promising, further clinical validation is important to access the sensor's practical utility in real-world scenarios, marking a crucial next step in this study. Moreover, this research establishes foundational data and reference points that can be used to enhance this sensor for future detection of various patient samples.