betadex and 4-aminophenol

Owing to the similar characteristics and physiochemical property of 2-aminophenol (2-AP) and 4-aminophenol (4-AP), the highly sensitive simultaneous electrochemical determination of 2- and 4-AP is a great challenge. In this paper, by electropolymerizing β-cyclodextrin (β-CD) and l-arginine (l-Arg) on the surface of carbon nanotubes@graphene nanoribbons (CNTs@GNRs) core-shell heterostructure, a P-β-CD-l-Arg/CNTs@GNRs nanohybrid modified electrode was prepared successfully, and it could exhibit the synergetic effects of β-CD (high host-guest recognition and enrichment ability), l-Arg (excellent electrocatalytic activity) and CNTs@GNRs (prominent electrochemical properties and large surface area), the P-β-CD-l-Arg/CNTs@GNRs modified electrode was used in the electrochemical determination of 2- and 4-AP, the results demonstrated that the highly sensitive and simultaneous determination of 2- and 4-AP is successfully achieved and the modified electrode has a linear response range of 25.0-1300.0 nM for both 2- and 4-AP, and the detection limits of 2- and 4-AP obtained in this work are 6.2 and 3.5 nM, respectively.

Topics: Aminophenols; Arginine; beta-Cyclodextrins; Complex Mixtures; Conductometry; Environmental Monitoring; Equipment Design; Equipment Failure Analysis; Graphite; Microelectrodes; Nanotubes, Carbon; Reproducibility of Results; Sensitivity and Specificity; Water Pollutants, Chemical

A rapid and sensitive electrochemical sensor based on disulfides bridged β-cyclodextrin dimer-functionalized multi-walled carbon nanotube (DBβ-CD-MWCNT) nanohybrids with higher supramolecular recognition capability was successfully constructed for the first time. Simultaneous trace analysis of three phenols (4-aminophenol, 4-AP; 4-chlorophenol, 4-CP; 4-nitrophenol, 4-NP) in tap-water and wastewater samples was performed based on the constructed sensor. Cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy were utilized to characterize the properties of the modified electrode. The proposed DBβ-CD-MWCNT-modified electrode displayed electrochemical signal superior to those of β-CD-MWCNT and MWCNT towards 4-AP, 4-CP, and 4-NP. Under optimal conditions, differential pulse voltammetry was used to simultaneously quantify 4-AP, 4-CP, and 4-NP within the concentration range of 0.01-20, 0.1-200, and 0.1-200 µM, respectively. The detection limits (S/N=3) of the DBβ-CD-MWCNT nanohybrid electrode for 4-AP, 4-CP, and 4-NP were 0.0042, 0.028, and 0.048 µM, respectively. Satisfactory results revealed that this proposed electrochemical sensor can provide a promising candidate for the simultaneous trace analysis of 4-AP, 4-CP, and 4-NP in environmental monitoring of water and wastewater samples. The present work might broaden the channel toward the application of bridged CD in the electrochemical sensing or biosensing.

Topics: Aminophenols; beta-Cyclodextrins; Biosensing Techniques; Chlorophenols; Dielectric Spectroscopy; Environmental Monitoring; Limit of Detection; Nanotubes, Carbon; Nitrophenols