Sensing and Bio-Sensing Research (Feb 2023)
Localized surface plasmon resonance biosensing of Mycobacterium tuberculosis biomarker for TB diagnosis
Abstract
Biosensors offer great advantages over conventional analytical techniques. Specifically, they can provide multiple capabilities such as user-friendly operation, real-time analysis, rapid response, high sensitivity and specificity, portability, label-free detection, and cost-effectiveness. As a result, this diagnostic approach is a point-of-care (POC) diagnostic and monitoring technology. In this study, for the first time, an optical biosensor chip was developed and analyzed using a localized surface plasmon resonance (LSPR) optical biosensing technique to monitor biomolecular interactions between mycolic acid TB antigen and anti-Mycobacterium tuberculosis antibody. Mycolic acid was successfully immobilized on a gold-coated biosensor chip and allowed to react with anti-Mycobacterium tuberculosis antibody. To enhance the detection signal from biomolecular binding events, gold nanoparticles (AuNPs) were used and successfully bioconjugated with goat anti-rabbit IgG H&L secondary antibody and characterized using ultraviolet-visible (UV–vis) spectroscopy, dynamic light scattering (DLS), Fourier-transform infrared (FTIR) spectroscopy, and subsequently introduced on the biosensing layer. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and atomic force microscopy (AFM) were used to characterize the biosensing surface. The optimized biosensor chip was analyzed using a custom-built biosensing transmission spectroscopy setup to perform LSPR biosensing. Our findings showed that mycolic acid was successfully immobilized on the biosensing surface and made it possible to capture anti-Mycobacterium tuberculosis antibodies. The LSPR optical biosensing technique was indeed successful in the detection of anti-Mycobacterium tuberculosis antibodies.
