20.500.12556/DiRROS-24711 Ultrasensitive electrochemical biosensor using carboxylated graphitic carbon nitride-nanogold composite for SARS-CoV-2 receptor binding protein The global response to COVID-19 has exposed critical gaps in rapid, ultrasensitive, and accessible diagnostic technologies, particularly in decentralised and low-resource environments. Herein, we report the development of an electrochemical biosensor designed for ultrasensitive detection of the SARS-CoV-2 spike receptor-binding domain (RBD) protein. This platform was rationally engineered nanocomposite combined with carboxylated graphitic carbon nitride (cGCN) and gold nanoparticles (AuNPs), which synergistically enhance surface reactivity, electron transfer efficiency, and biomolecular interface stability. Hybrid nanomaterials can overcome the kinetic and sensitivity barriers of traditional biosensors, and a cGCN/AuNP hybrid was fabricated on fluorine-doped tin oxide (FTO) electrodes and functionalized with in-house generated anti-RBD antibodies. Comprehensive physicochemical characterisation confirmed the successful integration and surface engineering of the composite. Using Differential Pulse Voltammetry, the sensor achieved a limit of detection (LOD) of 0.8 fM and demonstrated limit of quantification (LOQ) of 2.65 fM. This performance exceeds that of many existing SARS-CoV-2 antigen based biosensors and underscores the utility of rational nanomaterial design for high-precision point-of-care viral diagnostics. This approach is readily adaptable for detecting emerging viral pathogens and supporting future pandemic preparedness. graphitic carbon nitride true false true Elsevier Nizozemska Angleški jezik Ni določen © 2025 The Author(s). Neznano 2025-12-15 11:18:10 2025-12-15 11:18:10 2025-12-16 03:44:28 0000-00-00 00:00:00 2024 0 0 Nasl. z nasl. zaslona; Soavtorja iz Slovenije: Ivan Jerman, Raghuraj Singh Chouhan; Opis vira z dne 9. 7. 2025; str. 1-10 Vol. 215, [article no.] 114455 Aug. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-03-21 2025-07-01 2025-07-05 544.5/.6 1095-9149 10.1016/j.microc.2025.114455 241950723 https://www.sciencedirect.com/science/article/pii/S0026265X25018090?via%3Dihub 1 62d19a04-d99f-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36905 RAZ_Ramya_P.R._2024.pdf RAZ_Ramya_P.R._2024.pdf 1 BCD309CCDA854BFA84D66402FBDF7968 cf756d493d475d1f884776821f8102ce0b39dbedc0c46e991ce3629961c00568 20a18775-d9a0-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36908 Institut Jožef Stefan 0 0 0