Gold Nanoparticle‐Based Diagnostic Strip for Rapid Detection of Epstein–Barr Virus in Multiple Sclerosis

Epstein–Barr virus (EBV) is a significant global health concern due to its association with malignancies and autoimmune diseases like multiple sclerosis. Rapid, accessible detection methods are essential, especially in resource‐limited settings. Although polymerase chain reaction (PCR) remains the gold standard, its high cost and complexity underscore the need for simpler alternatives. This study presents a visual, user‐friendly biosensor using gold nanoparticles (AuNPs) for point‐of‐care detection of EBV DNA. A specific DNA probe was synthesized and conjugated to ∼30 nm spherical AuNPs via thiol linkages. Target EBV DNA induced nanoparticle aggregation, and subsequent HCl addition caused a distinct color change from red to blue, enabling visual detection. The biosensor achieved a detection limit of 200 pmol and produced results within 5 min. Nanoparticle uniformity and stability were confirmed through characterization. Compared to PCR, the biosensor demonstrated comparable specificity in cross‐validation experiments, while offering superior speed, cost‐effectiveness, and operational simplicity. This AuNP‐based biosensor represents a promising, low‐cost diagnostic tool for rapid EBV screening, particularly in low‐resource environments. Further validation with diverse clinical samples is recommended to enhance reliability and support broader application.