Differential impedimetric sensing of arboviruses using a lectin-modified hybrid polypyrrole-gold nanoparticle...

Arboviruses remain a major global public health concern, particularly Dengue (DENV), Zika (ZIKV), and Chikungunya (CHIKV), whose co-circulation and overlapping symptoms lead to challenging diagnosis. Due to their sensitivity and compatibility with diverse biorecognition elements, electrochemical biosensors have become attractive tools for viral detection. Hybrid materials play a central role in biosensing by integrating conductivity, high surface area, and chemical functionality at a single interface. Lectin-carbohydrate interactions enable selective targeting of glycan motifs on viral surface proteins, providing an alternative route for virus identification. Here, we report a lectin-based impedimetric biosensor for differential electrochemical sensing of DENV-2, DENV-4, ZIKV, and CHIKV. The sensing interface consisted of an electropolymerized polypyrrole (PPy) film combined with 4-mercaptobenzoic acid-functionalized gold nanoparticles (AuNPs@MBA) for Concanavalin A (ConA) immobilization. Atomic force microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy confirmed the successful assembly and electrochemical performance of the hybrid interface. The PPy-AuNPs@MBA platform enhanced electron transfer while providing a suitable surface for lectin immobilization. Distinct impedance responses were observed for the investigated arboviruses, consistent with differences in glycan presentation at the viral surface. The biosensor exhibited limits of detection of 0.578, 1.023, 0.620, and 0.761 PFU.mL⁻¹ for DENV-2, ZIKV, CHIKV, and DENV-4, respectively. These findings demonstrate the potential of the proposed hybrid platform as a lectin-based strategy for differential arbovirus sensing and support its further investigation as a complementary analytical tool for viral screening.