Bridged β-cyclodextrin-functionalized MWCNT with higher supramolecular recognition capability: The simultaneous electrochemical determination of three phenols

A rapid and sensitive electrochemical sensor based on disulfides bridged beta-cyclodextrin dimer-functionalized multi-walled carbon nanotube (DB beta-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 DB beta-CD-MWCNT-modified electrode displayed electrochemical signal superior to those of beta-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 mu M, respectively. The detection limits (S/N=3) of the DB beta-CD-MWCNT nanohybrid electrode for 4-AP, 4-CP, and 4-NP were 0.0042, 0.028, and 0.048 mu M, 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. (C) 2015 Elsevier B.V. All rights reserved.