Application of Prussian Blue modified carbon electrodes for amperometric detection of amyloid-β peptides by flow injection analysis

•Specific oxidation of aβ peptides on carbon SPE at 0.70 and 0.95 V was observed, using FIA.•A pronounced catalytic effect of Prussian Blue was found for peptides lacking the Tyr-residue.•Practically no effect of Prussian Blue was observed for Tyr-containing aβ mutants;.•Berlin green is reduced to Prussian Blue by a peptide thus setting up a catalytic cycle. Prussian Blue (PB) modified carbon screen printed electrodes (SPE) were successfully applied for detection of amyloid-β (Aβ) peptides of various lengths and amino acid sequences by amperometric flow injection analysis (FIA). A pronounced catalytic effect of PB (10- to 27-fold current increase) was found for peptides lacking the Tyr-10 residue, viz. Aβ(1–7)-D7H, rat Aβ(1–16), and Aβ(1–16)-Y10A, while practically no effect of PB was observed for Aβ(1–16)-D7H, Aβ(1–16)-H6R, and Aβ(1–16)-E11A mutants. Only a 1.5-fold current enhancement was observed for Aβ(1–16) oxidation on SPE/PB, compared to SPE, by FIA. Therefore, the combination of FIA and SPE/PB may open a new avenue for the electrochemical investigation of peptides of interest lacking inherently electroactive residues (Tyr, Trp, Cys, His, and Met), as exemplified by naturally occurring and artificial Aβ mutants containing no Tyr-10 residue. [Display omitted]