Role of Phe-D5 isotopically labeled analogues of bradykinin on elucidation of its adsorption mode on Ag, Au, and Cu electrodes. Surface-enhanced Raman spectroscopy studies


Correspondence to: Edyta Proniewicz, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30–060 Krakow, Poland



Raman (RS), surface-enhanced Raman scattering (SERS), electrochemistry, and isotopic effect methods were used to characterize selective adsorption of two isotopically labeled bradykinin analogues, [(Phe-D5)5]BK and [(Phe-D5)8]BK, a hormone which is known to be involved in small-cell and non-small-cell lung carcinoma and prostate cancer. The investigated analogues contain Phe residue, at position 5 or 8 in the amino acid sequence, substituted by Phe-D5 (five protons of L-phenylalanine ring substituted by deuterium). [(Phe-D5)5]BK and [(Phe-D5)8]BK were immobilized onto electrochemically roughened Ag, Au, and Cu electrode surfaces under different applied electrode potentials (−1.000 V to 0.200 V) in an aqueous solution containing 0.01 M phosphate buffer (pH = 7.0) and 0.1 M Na2SO4. Based on the analyses of the spectral profiles in the 920 – 1050 cm−1 spectral range, specific conclusions were drawn with respect to the Phe⋅⋅⋅metal interactions and changes in the interaction that occurred when the adsorption conditions were varied. Copyright © 2013 John Wiley & Sons, Ltd.