The self‐assembly of redox active peptides: Synthesis and electrochemical capacitive behavior

Abstract

The present work reports on the synthesis of a redox-tagged peptide with self-assembling capability aiming applications in electrochemically active capacitive surfaces (associated with the presence of the redox centers) generally useful in electroanalytical applications. Peptide containing ferrocene (fc) molecular (redox) group (Ac-Cys-Ile-Ile-Lys(fc)-Ile-Ile-COOH) was thus synthesized by solid phase peptide synthesis (SPPS). To obtain the electrochemically active capacitive interface, the side chain of the cysteine was covalently bound to the gold electrode (sulfur group) and the side chain of Lys was used to attach the ferrocene in the peptide chain. After obtaining the purified redox-tagged peptide, the self-assembly and redox capability was characterized by cyclic voltammetry (CV) and electrochemical impedance-based capacitance spectroscopy techniques. The obtained results confirmed that the redox-tagged peptide was successfully attached by forming an electroactive self-assembled monolayer onto gold electrode. The design of redox active self-assembly ferrocene-tagged peptide is predictably useful in the development of biosensor devices precisely to detect, in a label-free platform, those biomarkers of clinical relevance. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 357-367, 2016.

Antimicrobial activity of RP-1 peptide conjugate with ferrocene group

“…Ferrocene carboxylic acid, purchased from Sigma (purity 97%), was coupled to the N-terminus of the peptide by using HCTU activators (O-(6-chloro-benzotriazoyl-1-yl) N, N, N'-hexafluorophosphate) N'-tetramethyluronium hexafluorophosphate) and DIPEA (N, N, N-diisopropylethylamine). Cleavage of the resin and removal of the side chain protecting groups were performed with 95% TFA (trifluoroacetic acid), 2.5% H 2 O and 2.5% triisopropylsilane (TIS) for 2 h [44]. The peptide was precipitated with ether anhydrous, separated from soluble non-peptide material by centrifugation, washed 3 times with ether and extracted in a mixture of 0.045% (v/v) TFA/H 2 O and 0.036% (v/v) TFA /ACN (Acetonitrile).…”

Charge transport and energy storage at the molecular scale: from nanoelectronics to electrochemical sensing

“…18 Fig. 5 Electrochemical IS analysis of a 1.6 nm thickness redox-tagged peptide molecular film 40 in 'wet' measurement conditions. (a) Values of C m measured at two different potential conditions: (red) inside and (white) outside of the faradaic window.…”

A dual marker label free electrochemical assay for Flavivirus dengue diagnosis

“…, where C r is the electrochemical or redox capacitance per cm 2 (estimated by the diameter semicircle of the capacitive Nyquist plot, as detailed in references Fernandes et al, 2014)), k B is the Boltzmann constant, T is the absolute temperature (293 K), F the Faraday constant, and e the elementary charge (Piccoli et al, 2016). Γ Fc 11 results obtained using redox capacitance were compared with those estimated from classical voltammetry, Γ QF A = / and Q is the charge obtained by the integration peak of the reduction/oxidation process after compensating for non-faradaic contributions (Walczak et al, 1991).…”