Electrochemical Detection of Thiols

J. Wang, J. Zima, N.S. Lawrence and M.P. Chatrathi, Microchip capillary electrophoresis with electrochemical detection of thiol-containing degradation products of V-type nerve agents, Anal. Chem., 76 (2004) 4721-4726. 

T. Inoue and J. R. Kirchhoff, Electrochemical Detection of Thiols with a Coenzyme Pyrroloquinoline Quinone Modified Electrode. Anal. Chem. 72, 5755-5760 (2000). 

The electrochemical detection of thiols is one example of great importance that illustrates the efficiency of metaUophthalocyanines, especially cobalt phthalocya-nine (CoPc), to act as a mediator in the electrocatalytic oxidation of molecules containing this group. Santhiago et al. [34] reported an interesting configuration of... 

Rangel Argote M, Sanchez Guillen E, Gutierrez Porras AG et al (2014) Preparation and characterization of electrodes modified with pyrrole surfactant, multiwalled eaibon nanotubes and metallophthalocyanines for the electrochemical detection of thiols. Electraanalysis 26 507-512... 

Xu H, Sun W, Zhu H, Du F, Liu F, Xu Y, He Y (2013) Design of electrochemical detection of thiols based on the cleavage of the disulfide bond coupled with thionine modified gold nanoparticle-assisted amplification. Chem Commun 49 9603-9605... 

Two different formats of electrochemical detection of thrombin-aptamer interactions using MB were recently developed [32,49]. The aptamer was modified at one end by thiol group and at the other end by MB. Without thrombin, the MB possesses the reduction signal. Addition of thrombin shifted equilibrium from unfolded to folded aptamer conformation. This resulted in an increase in distance of MB from the electrode. As a result the reduction signal decreased. 

Electrochemical (EC) techniques provide an alternative way to detect sulfur containing molecules. Earlier methods of EC detection involve the application of a gold/mercury electrode.15 Platinum and gold electrodes have also been used for anodic detection of thiols,16 but this requires high oxidation potentials, which complicates analytical applications. Thus, chemically modified electrodes with inorganic or organic mediators have been employed to facilitate electron-transfer between the electrode and the analyte, and therefore reduce the oxidation potential. Recently, pyrroloquinoline quinone (PQQ) modified electrodes have been developed for detection of endo- and exogenous thiols.17... 

Fig. 6. (A) The electrochemical detection of hybridization on Au electrode surface. Probe oligonucleotides with 5 -thiol are incubated on the Au surface for 12h. Strong covalent bond between thiols and Au surface results in the formation of the probe-modified electrode (A1), noncomplementary oligonucleotides are incubated with the probe-modified electrode (A2) however, no hybridization takes place between these two strands (A3), the redox label, Hoechst 33258, is incubated with the probe-modified-electrode (A4), since the redox label cannot intercalate with the single-strand probe oligonucleotides on the surface, a small electrochemical current response is obtained (A5). The current intensity at the peak potential (-0.6V) is recorded relative to the background response of the blank buffer solution (dashed grey line). (B) The electrochemical detection of hybridization on Au electrode surface. Probe oligonucleotides with 5 -thiol are incubated on the Au surface for -12 h for the preparation of the probe-modified electrode (B1), target oligonucleotides are...

The characteristic electrochemical behavior of enzyme, protein and Upid monolayers adhered to SAMs derived from thiols on gold surfaces may be applied to the development of biosensors. The gold electrodes resulting from incorporation of monensin (203) and vaUnomycin (204) into bilayers, consisting of the SAMs of aUsanethiol covered by a Upid monolayer, have high sensitivity for monovalent ions . A gold electrode with a SAM of a modified /3-cyclodextrin was proposed for electrochemical detection of organic compounds . 

T. Kuninori and J. Nishiyama, Measurement of biological thiols and disulfides by high performance liquid chromatography and electrochemical detection of silver mercaptide formation. Anal Biochem., 1991, 197, 19-24. 

Y.P. Sun, D.L. Smith and R.E. Shoup, Simultaneous detection of thiol-containing and disulfide-containing peptides by electrochemical high-performance liquid-chromatography with identification by mass-spectrometry. Anal. Biochem., 1991, 197, 69-76. 

Fig. 9.13 Electrochemical detection of nucleic acid with the bioelectronic sensor based on a sandwich assay. A target nucleic acid is shown to anneal to a capture probe and a ferrocene-labeled signaling probe [58]. The thiol-terminated oligophenylethynyl molecules serve as molecular wires and provide a...

Zhou, J. O Shea, T.J. Lunte, S.M. Simultaneous Detection of Thiols and Disulfides by Capillary Electrophoresis-Electrochemical Detection Using a Mixed Valence Ruthenium Cyanide-Modified Microelectrode. J. Chromatogr. A 1994 680, 271-277. 

Dulay, S., Lozano-Sanchez, R, Iwoha, E. et al (2011) Electrochemical detection of celiac disease-related anti-tissue transglutaminase antibodies using thiol based surface chemistry. Biosens. Bioelectron., 26, 3852-3856. 

---