An <scp>Enzyme‐Free</scp> Amperometric Sensor Based on <scp>Self‐Assembling Ferrocene‐Conjugated</scp> Oligopeptide for Specific Determination of <scp> <i>L</i> ‐Arginine </scp>

An enzyme-free amperometric sensor based on a heptadecapeptide possessing an electroactive ferrocene (Fc) linker as ferrocene-Gly-Gly-Gly-Gly-Phe-Gly-His-Ile-His-Glu-Gly-Tyr-Gly-Gly-Gly-Gly-Lys-(CH2)4-dithiocyclopentane self-assembled gold substrate was designed and fabricated for specific determination of L-arginine (L-Arg). The detection mechanism is conformational change surface-immobilized peptide induced by the target L-Arg, which confirmed via SEM, TEM, AFM, XPS, SPR studies. binding affinity recognition feasibility immobilized non-specific peptides were also assessed using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), differential pulse (DPV). proposed method can serve “signal-on” L-Arg down to 31 pmol/L with broad linear range (0.0001 10 μmol/L). Furthermore, Fc-conjugated successfully applied in pig serums recovery rate 97.5%—106.9%, its test results are good agreement that chromatographic instrument, evidencing oligopeptide-based be served simple biosensing platform towards future application. Appendix S1: Supporting Information Please note: publisher not responsible content or functionality any supporting information supplied authors. Any queries (other than missing content) should directed corresponding author article.