20.500.12556/DiRROS-24748 Detection of specific antibodies against SARS-CoV-2 spike protein via ultra-sensitive bio-functionalized carbonnitride-reduced graphene oxide electrochemical immunosensing platform in real samples In this work, we fabricate a facile de novo synthesis route to prepare bio-functionalized carbon nitride-reduced graphene oxide with chitosan (Chi) nanocomposite (C3N4/RGO/Chi). The nitrogen-rich C3N4 has been synthesized through facile and low-cost thermal oxidation and offers a metal-free and highly active surface for synergistic modification with RGO and Chi. Moreover, the synergistically incorporated C3N4/RGO and biopolymer improve the electrocatalytic activity, provide surface functionalities, and enhance electroconductivity for immunosensing applications. Consequently, the bio-functionalized C3N4/RGO nanocomposite provides a suitable substrate for the immobilization of SARS-CoV-2 RBD spike protein. The immunosensor detects SARS-CoV-2 antibodies in a wide detection range from 10 zg mL−1 (10 × 10−21 g mL−1) to 100 ng mL−1 with an ultra-low detection limit (LOD) of 3.31 zg mL−1. The validation of the immunosensor was also carried out on spiked serum samples, which show a linear detection range of 100 ag mL−1 to 100 ng mL−1 and a LOD of 1.73 ag mL−1. Nevertheless, the clinical diagnostic application of the immunosensor is validated through the examination of real serum samples from COVID-19 patients. The results suggest that the immunosensor can be efficiently used as a screening platform to distinguish between positive and negative samples with high accuracy. The findings of the work have the potential to translate the immunosensing strategy into next-generation point-of-care testing (POCT) of various infectious diseases. SARS-CoV-2 detection nanomaterials zaznavanje nanomateriali true false true The Royal Society of Chemistry Združeno kraljestvo Angleški jezik Slovenski jezik © 2023 The Author(s). Neznano 2025-12-16 13:46:30 2025-12-16 13:46:30 2025-12-17 03:58:06 0000-00-00 00:00:00 2023 0 0 Nasl. z nasl. zaslona; Soavtorja iz Slovenije: Raghuraj Singh Chouhan, Ivan Jerman; Opis vira z dne 12. 10. 2023; str. 5291-5304 Vol. 4 iss. 21 Nov. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2023-07-12 2023-10-03 2023-10-11 620.3 2633-5409 10.1039/D3MA00399J 168038659 https://pubs.rsc.org/en/content/articlelanding/2023/ma/d3ma00399j 1 40f06a7a-da7d-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36986 RAZ_Abubakar_Sadique_Mohd._2023.pdf RAZ_Abubakar_Sadique_Mohd._2023.pdf 1 AFB4903541FCE37AE4C24CFE67E1964C 35bbe84be1b4890c0d9ee4fc24d2b78c955c67c28602411c4a2b896274646392 b376b053-da7d-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36989 Institut Jožef Stefan 0 0 0