Abstract
The demand for rapid and scalable biosensing technologies has motivated the development of antibody-free platforms capable of operating in complex sample environments. Here, we report an electrochemical biosensor based on engineered M13 bacteriophages displaying a SARS-CoV-2 spike S1–binding peptide immobilized on a reduced graphene oxide (rGO) transducer. The sensor employs a chemiresistive detection mechanism under a fixed low-voltage bias, enabling rapid electrical readout following target binding. Detection of S1 protein was achieved in buffer and in spiked complex matrices, including fetal bovine serum, pasteurized milk, and wastewater, demonstrating matrix tolerance under the tested conditions. The biosensor response is evaluated using a statistically defined binary detection criterion, with an operational limit of detection of 10⁻4 pg/mL in buffer. Compared to a previously reported antibody-functionalized rGO sensor fabricated using the same platform, the phage-based biosensor exhibits comparable sensitivity while offering advantages in genetic tunability and production scalability. While the present study focuses on proof-of-concept validation using spiked samples, these results highlight the potential of engineered phage–graphene interfaces as adaptable biorecognition elements for rapid electrochemical protein sensing in complex environments.
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Acknowledgement
The authors would like to acknowledge Dr. Chia-Yun Lai (Postdoctoral Fellow, Mechanical & Nuclear Engineering, Khalifa University of Science and Technology) for training and assisting HYA to carry out the atomic force microscopy (AFM) measurements. We also acknowledge Professor Matteo Chiesa (Mechanical & Nuclear Engineering, Head of the Laboratory for Energy and Nano Science (LENS) at Khalifa University of Science and Technology) for facilitating access to and providing training at Khalifa University’s AFM facility. Figures in this work were created with BioRender.com.
Funding
This work was supported by a Research Innovation Student Grant (RIG-S) by Khalifa University (RIG-2023-032), the Center for Membranes and Advanced Water Technology (CMAT) at Khalifa University (Award No. RC2-2018-009), and the Center for Biotechnology (BTC) at Khalifa University.
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A.F.Y., H.A.S., and S.W.H. conceived and supervised the project. H.Y.A. performed the phage construction, rGO synthesis, biosensor fabrication, and materials characterization. S.P. and L.T. assisted in biosensor fabrication and data analysis. M.I.H. and L.T. contributed to SEM, EDS, and XRD imaging and analysis. H.Y.A. and L.T. carried out biosensor testing and electrochemical measurements. Figures were prepared by H.Y.A. and A.F.Y. The initial manuscript draft was written by H.Y.A., and all authors except M.I.H. contributed to revisions. A.F.Y., S.W.H., and H.A.S. secured project funding. All authors reviewed and approved the final manuscript.
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Alshehhi, H.Y., Tizani, L., Palanisamy, S. et al. An engineered M13 phage–rGO electrochemical biosensor for rapid detection of viral protein in complex matrices. Sci Rep (2026). https://doi.org/10.1038/s41598-026-37008-w
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DOI: https://doi.org/10.1038/s41598-026-37008-w
