Studying the Role of Modified Aptamer-8 for Efficient Detection of Immunoglobin-G Antibodies.

Abstract

Immunoglobulin G (IgG) plays a critical role in the diagnosis of multiple pathological conditions, including autoimmune hepatitis, hepatitis B virus (HBV), chickenpox, and MMR (Mumps, Measles, and Rubella). However, dependable, sensitive, and selective IgG detection remains a challenge. The recent outbreak of SARS-CoV-2 has highlighted the significance of IgG biosensing. Therefore, this study aims to develop a novel IgG biosensing platform with improved reliability, sensitivity, and selectivity. The proposed biosensing platform consists of Aptamer 8 as a biorecognition element and gold interdigitated electrodes (IDEs) modified with perfluoro decanethiol (PFDT) as its main constituents. The IDEs were immersed in the PFDT solution for the self-assembled monolayer (SAM) deposition process for 24 hours at room temperature (RT), and then dried in a glove box with a nitrogen atmosphere. Aptamer 8 was used to functionalize PFDT-IDEs, and several dilutions of IgG were incubated onto the biosensor for the detection studies. Contact angle, SEM, AFM, XRD, FTIR spectroscopy, and electrochemical studies were done for characterization and detection studies. The proposed biosensing platform showed a limit of detection (LOD) of 13 ug/ml. Characterization studies demonstrated the successful modification of PFDT on IDEs and the functionalization of Aptamer 8 on PFDT-IDEs. Electrochemical studies revealed a significant increase in the current response upon the incubation of IgG on the biosensor. The proposed IgG biosensing platform with Aptamer 8 and gold interdigitated electrodes modified with perfluoro decanethiol showed improved reliability, sensitivity, and selectivity. This biosensing platform has potential applications for high throughput systems and point-of-care detection of IgG and other biomolecules. Future studies should focus on optimizing the biosensor's performance and exploring its application in clinical settings.