Abstract
Electrochemical biosensors require robust, well-controlled biointerfaces, but existing protein immobilization chemistries are slow and poorly defined. Here we report an interfacial electrochemical tyrosine-click (i-eY-Click) strategy that enables rapid (<3 min), chemoselective covalent attachment of native proteins under physiological conditions. At mild potentials (+0.36 V vs Ag/AgCl), electrode-grafted 4-phenylurazole is oxidized in situ to phenyltriazolinedione intermediates that react specifically with tyrosine residues, without genetic modification or soluble catalysts. i-eY-Click displays ~20-fold faster kinetics than conventional amide coupling while preserving protein activity. Implemented on carbon microelectrode arrays, it yields well-controlled antibody monolayers and supports multiplexed cytokine sensing in native serum with markedly improved sensitivity, detection limits and reproducibility. We further use this platform for in vivo serum immunoprofiling in a nanoplastic exposure model, revealing charge-dependent cytokine signatures and delayed inflammatory responses to polylactic acid particles. i-eY-Click thus provides a general, chemistry-driven route to high-performance biointerfaces for multiplexed immunosensing and biomarker profiling.
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All data supporting the findings of this study are available within this paper and Supplementary Information. Source data are provided with this paper.
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This study did not generate new code or algorithms. All analyses were performed using standard, published software packages and parameters as described in the Methods section.
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Acknowledgements
We acknowledge the financial support from the National Natural Science Foundation of China (Grant nos. 22374010 to Y.J., Grant no. 22134002 for L.M.), Fundamental Research Funds for the Central Universities (2243300002 and 310432103 to Y.J.), the National Key R&D Program of China (Grant no. 2024YFA1211600 to Y.J.), and the Beijing Nova Program (20230484414 to Y.J.).
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Y.J. conceived the idea. K.S. and C.L. performed the chemical synthesis. K.S. designed and performed electrode modification and characterization. K.S. and Q.M. performed data collection. K.S. and Y.L. performed data analysis. K.S. and Y.J. wrote the manuscript with contributions from all authors. Y.J. and L.M. supervised and guided the project.
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Song, K., Liu, Y., Ma, Q. et al. Electrochemical tyrosine-click bioconjugation enables multiplexed cytokine sensing and immunoprofiling in native serum. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70815-3
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DOI: https://doi.org/10.1038/s41467-026-70815-3
