Chemically Bonded Carbon Nanotube Film to a Nanostructured Gold Electrode for Electrochemical Sensing of Hydrogen Peroxide

Abstract

This paper describes the first application of a covalently attached carbon nanotube film to the nanostructured gold electrode for the electrochemical detection of hydrogen peroxide. The electrodes were made by diazonium salt grafting to the gold surface with the subsequent attachment of carbon nanotubes using a low-temperature synthesis method. The introduction of properly aligned carbon nanotubes significantly increased the electroactive surface area and the current response. Covalent bonding of the nanotubes to gold resulted in a very high stability of the signal under the oxidative conditions. After 540 h of exposure to a high oxidative potential, the current response remained stable, having negligible deviations between the runs. Hydrogen peroxide detection involves an indirect enzyme-free oxidation mechanism, allowing for analysis at low potentials. The use of such a mechanism allows for classifying the system as a fourth-generation H 2 O 2 sensor. Because of the low working potential, a 20-fold excess of fructose, creatinine, dopamine, uric acid, citric acid, and ascorbic acid did not interfere with hydrogen peroxide detection. The presence of functional groups on the carbon nanotube surface provides possibilities for simple functionalization. As an example, the fabricated electrodes were successfully modified with glucose oxidase for glucose quantification.

Creating covalent bonds between Cu and C at the interface of metal/open-ended carbon nanotubes

“…The robustness of the grafted aminophenyl linker has recently been employed for the development of an electrochemical hydrogen peroxide sensor. It has shown impressive current response stability when exposed to high oxidative potentials for 540 h. 101 …”

Sidewall Chemical Bonding of Aligned Carbon Nanotubes with Metals: A Promising Route for Hybrid Materials Development

“…This enhancement would allow for the fabrication of smaller and robust electrodes for sensors. CNT bonded to Au metal has been demonstrated as a selective and sensitive sensor for the detection of hydrogen peroxide in aqueous medium already . After CNT modification, the Δ E p value decreased for SS, indicating improved electrochemical kinetics but increased for ITO, while it did not change for the Au.…”

Ferrocene-Containing Gallic Acid Derivative Modified Carbon Nanotubes Electrode for Fast and Simple Simultaneous or Selective Detection of Cytostatic from Aqueous Solutions

“…Drop casting is the easiest and fastest technique for modifying electrodes that are applied to checking the electrocatalytic activity of modifiers towards target analytes, yet without good stability, while paste mixing is also an easy and cheap method for integrating the modifier within the electrode composition, characterized by greater stability [16]. A large spectrum of modifiers, including nanostructured carbons, have been reported for the modification of carbon-based materials through drop casting [17,18] and paste mixing [19][20][21][22]. Also, carbon nanotubes (CNTs) are well-known as porous nanostructures characterized by a high surface area, high electrical conductivity, significant mechanical strength, and chemical stability [20,21] making them suitable as both a modifier [23] and substrate [20][21][22].…”