In Vivo Monitoring of the Thiols in Rat Striatum by Liquid Chromatography with Amperometric Detection at a Functionalized Multi‐Wall Carbon Nanotubes Modified Electrode

Abstract

A new chemically modified electrode (CME) was fabricated, which was based on the immobilization of multi-wall carbon nanotubes fuctionalized with carboxylic group (MWNT-COOH). The results indicated that the CME exhibited efficiently electrocatalytic oxidation for l-cysteine and glutathione with relatively high sensitivity, stability and long-life. Coupled with HPLC, the MWNT-COOH CME was utilized for amperometric detection of the thiols. The peak currents of l-cysteine and glutathione were linear to their concentrations ranging from 3.0 Â 10 À7 to 1.0 Â 10 À3 mol/L with the calculated detection limit (S/N 3) of 1.2 Â 10 À7, 2.2 Â 10 À7 mol/L, respectively. The method had been successfully applied to assess the contents of l-cysteine and glutathione in rat striatal microdialysates.

A Disposable Biosensor for Organophosphorus Nerve Agents Based on Carbon Nanotubes Modified Thick Film Strip Electrode

“…This large increase in current at the MWCNT-SPE can be attributed to the catalytic behavior of CNT toward thiocholine. The electrocatalytic oxidation of thiocholine, which also contains a thiol moiety, by the use of a MWCNT modified electrode, is in agreement with recently reported use of carbon nanotubes for the detection of thiols such as cysteine and glutathione [12]. Since the operation of a sensor at a low potential is analytically more desirable to reduce the electrochemical interferences for high selectivity, a low operating potential of 200 mV was chosen to demonstrate the applicability of this sensor for the sensitive detection of thiocholine.…”

“…The possibility of the promotion of electron transfer reactions at a lower overpotential due to their structure dependent metallic character and their high surface area provide ground for unique biochemical sensing systems [9]. The electrochemistry of CNT modified electrodes has been studied and it has been shown that they have stable electrochemical behavior and catalyze the electrochemical reaction of dopamine, epinephrine, ascorbic acid [10], NADH [11], cysteine, glutathione [12], and hydrogen peroxide [13].…”

Binding of Acetylcholinesterase to Multiwall Carbon Nanotube‐Cross‐Linked Chitosan Composite for Flow‐Injection Amperometric Detection of an Organophosphorous Insecticide

“…The electrocatalytic action of MWNTs was also observed for the oxidation of some compounds containing a thiol moiety, such as cysteine and glutathione. [4,34] A high background current was observed when the MWNTs were directly coated on the electrode surface and then covered with cross-linked chitosan membrane, instead of entrapment in cross-linked chitosan membrane. Following experiments were carried out by using AChE/CMC/GCE configuration.…”

Overoxidized polypyrrole/multi-walled carbon nanotubes composite modified electrode for in vivo liquid chromatography–electrochemical detection of dopamine

“…For example, they had been successfully used in oxidation of dopamine [15], electrochemistry of protein [16], and in electrocatalysis of NADH [17]. Our previous studies had also showed an excellent electrochemical reactivity for oxidization of thiol compounds [18]. All these indicate that the performance of carbon nanotubes is superior to many other carbon electrodes in terms of reaction rates and reversibility.…”