Oxygen Plasma Exfoliated Vertically-Aligned Carbon Nanotubes as Electrodes for Ultrasensitive Stripping Detection of Pb²⁺

Abstract

In the present paper we report the production of vertically aligned carbon nanotubes exfoliated (at the tips) by oxygen plasma for electrochemical applications. The fast and dry process produces graphene oxide tips and oxygen functionalization. The electrodes are evaluated by cyclic voltametry by ferri/ferrocyanide redox couple and applied for electrochemical detection of lead (II) by differential pulsed anodic stripping voltammetry. The electrode presents high sensitivity (35.47 uA.uM −1 ) and low detection limit (48.3 pM). As far as we know, this is the lowest LoD in comparison with other works using CNT or graphene electrodes. The high electrochemical response is attributable to high density of functionalized edges on carbon nanotubes tips.

Robust, flexible, freestanding and high surface area activated carbon and multi-walled carbon nanotubes composite material with outstanding electrode properties for aqueous-based supercapacitors

“…D* band is related to amorphous-like carbons (e.g., defectrich short carbon layers). The D # band is assigned to oxygen functional groups onto carbon surface such as C-O, C=O, COOas reported by us elsewhere (59)(60)(61)(62)(63). Therefore, we refer to D # as Carbon with functional oxygen group band, CfO.…”

A gold electrode modified with amino-modified reduced graphene oxide, ion specific DNA and DNAzyme for dual electrochemical determination of Pb(II) and Hg(II)

“…A comparison of these three cases demonstrates that the electrochemical DNA-based sensor is considerably helpful in detecting Pb 2+ with a higher ΔR ct value of 0.46 kohm. For the NH 2 -rGO sample, an interesting result showed a decrease in the R ct value after the plasma treatment, indicating that the electrochemical performance of rGO after plasma modification improved [23]. As discussed above, amino groups were produced on the NH 2 -rGO surface, further leading to electrostatic interaction between positively charged ammonium group and the negatively charged phosphate groups on single strand DNA in the aqueous solution [18].…”

Preparation and electroanalytical applications of vertically aligned carbon nanotubes

“…Saito et al 82 reported the application of a VACNT-GO electrode for the determination of lead (II). The electrode was initially evaluated by cyclic voltammetry using the electrochemical ferri/ferrocyanide redox couple.…”