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Updated: Nov 4, 2025

Author Spotlight: Advancing Antiviral Strategies Through Novel Immunocapture and Mass Spectrometry Techniques
Published on: January 12, 2024
Simultaneous detection of the spike and nucleocapsid proteins from SARS-CoV-2 based on ultrasensitive single molecule
Qiyong Cai1, Jingjing Mu1, Yang Lei1
1College of Chemistry, Green Catalysis Center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou Key Laboratory of Functional Nanomaterial and Medical Theranostic, Zhengzhou University, Zhengzhou, 450001, Henan, People's Republic of China.
Abstract:
Nucleic acid detection technology based on polymerase chain reaction (PCR) and antibody detection based on immunochromatography still have many problems such as false negatives for the diagnosis of coronavirus disease 2019 (COVID-19). Therefore, it is of great importance to develop new techniques to improve the diagnostic accuracy of COVID-19. We herein developed an ultrasensitive, rapid, and duplex digital enzyme-linked immunosorbent assay (dELISA) for simultaneous detection of spike (S-RBD) and nucleocapsid (N) proteins of SARS-CoV-2 based on a single molecule array. This assay effectively combines magnetic bead encoding technology and the ultrasensitive detection capability of a single molecule array. The detection strategies of S-RBD protein and N-protein exhibited wide response ranges of 0.34-1065 pg/mL and 0.183-338 pg/mL with detection limits of 20.6 fg/mL and 69.8 fg/mL, respectively. It is a highly specific method for the simultaneous detection of S-RBD protein and N-protein and has minimal interference from other blood proteins. Moreover, the spike assay showed a satisfactory and reproducible recovery rate for the detection of S-RBD protein and N-protein in serum samples. Overall, this work provides a highly sensitive method for the simultaneous detection of S-RBD protein and N-protein, which shows ultrasensitivity and high signal-to-noise ratio and contributes to improve the diagnosis accuracy of COVID-19.

