Ascorbyl and hydroxyl radical generation mediated by a copper complex adsorbed on gold.

Ascorbyl and hydroxyl radical generation mediated by a copper complex adsorbed on gold.

Romo, Adolfo I B;Dibo, Vitória S;Abreu, Dieric S;Carepo, Marta S P;Neira, Andrea C;Castillo, Ivan;Lemus, Luis;Nascimento, Otaciro R;Bernhardt, Paul V;Sousa, Eduardo H S;Diógenes, Izaura C N;
Dalton transactions (Cambridge, England : 2003) 2019
178
romo2019ascorbyldalton

Abstract

This work presents the results obtained for a thioether derivative of bipyridine, (E,Z)-1-(4'-methyl-[2,2'-bipyridine]-4-yl)-N-(4(methylthio)phenyl)methanimine (4-mbpy-Bz-SMe), and its copper complex [CuII(4-mbpy-Bz-SMe)2]2+. Electronic spectra acquired at 183 K of the cuprous complex [CuI(4-mbpy-Bz-SMe)2]+ generated in situ indicated the formation of the peroxodicopper compound {[CuII(4-mbpy-Bz-SMe)2]2(μ-O22-)}2+. A gold electrode modified with [CuII(4-mbpy-Bz-SMe)2]2+ (Au/[Cu]) was fully characterized by SERS spectroscopy, electrochemistry and impedance spectroscopy thus showing adsorption occurs through the sulfur atom of the 4-mbpy-Bz-SMe moieties. DNA cleavage assays showed the copper complex, in solution and adsorbed on gold, degrades DNA if reducing conditions are maintained, i.e. ascorbic acid (H2AA) in solution or applied potentials more negative than 0.12 V vs. Ag/AgCl (CuI form). The electron paramagnetic resonance (EPR) spectra obtained for the electrolyzed solution (Eapl = -0.2 V, no H2O2) and for the solution containing [CuII(4-mbpy-Bz-SMe)2]2+ and H2O2 showed hydroxyl radical, HO˙, generation had occurred. The cyclic voltammograms obtained with H2AA in solution at Au/[CuII(4-mbpy-Bz-SMe)2]2+ as the working electrode showed a one-electron reaction leading to the ascorbyl radical (HA˙), which was detected by EPR. The current assigned to the electrode oxidation of HA˙ to AA decreased with the addition of catalase, a scavenger of H2O2, meaning peroxide is involved in the mechanism.

Citation

ID: 43009
Ref Key: romo2019ascorbyldalton
Use this key to autocite in SciMatic or Thesis Manager

References

Blockchain Verification

Account:
NFT Contract Address:
0x95644003c57E6F55A65596E3D9Eac6813e3566dA
Article ID:
43009
Unique Identifier:
10.1039/c9dt01726g
Network:
Scimatic Chain (ID: 481)
Loading...
Blockchain Readiness Checklist
Authors
Abstract
Journal Name
Year
Title
5/5
Creates 1,000,000 NFT tokens for this article
Token Features:
  • ERC-1155 Standard NFT
  • 1 Million Supply per Article
  • Transferable via MetaMask
  • Permanent Blockchain Record
Blockchain QR Code
Scan with Saymatik Web3.0 Wallet

Saymatik Web3.0 Wallet