Abstract
Staphylococcus aureus is the Gram-positive, immobile, round-shaped bacterium usually existing on wounds, marine environments, and contaminated food. α-Hemolysin (also called \(\alpha \) -toxin), a common pore-forming toxin that presents in most S. aureus strains with the ability to penetrate the host cell membrane, leading to osmotic swelling and cell death, appears to be a potential biomarker for detection. Based on a sandwich format, this study developed a lateral flow immunoassay (LFIA) targeting \(\alpha \) -toxin to detect S. aureus. Silver enhancement method was applied to enhance the test line’s signal and, therefore, improve the limit of detection (LOD). This method relies on the accumulation on AuNP surface of silver atoms which come from silver nitrate salt after being reduced by reducing agent. The developed LFIA could detect the target antigen within approximately 20 min with no cross-reactivity. The LOD was increased 10-fold after the silver enhancement, from 105 to 104 CFU/mL of bacteria suspensions. The results indicated that \(\alpha \) -toxin is a promising target to detect S. aureus. Targeting \(\alpha \) -toxin not only can be a potential detection approach but also a tool for measuring toxicity.
