Efficient Electropolymerization of Β-Cd on Pretreated Carboxylated Multiwalled Carbon Nanotubes/Gce to Improve Electrochemical Simultaneous Detection of Nitroaromatic Compounds

Abstract

A two-step method (esterification reaction, followed by electropolymerization) was performed to immobilize β-CD on MWCNTs-COOH to synthesize E 30 -C@M/GCE sensor. Compared to direct electropolymerization of β-CD on MWCNTs-COOH/GCE or β-CD/MWCNTs-COOH/GCE, this two-step method not only improved dispersity of MWCNTs-COOH, but also bound more β-CD units on tubes of MWCNTs-COOH, which was confirmed by IR and SEM. The obtained E 30 -C@M material combines the individual advantages of β-CD and MWCNTs-COOH, and possesses a synergistic effect on its excellent electrochemical performance. Cyclic voltammetry (CV) results showed that E 30 -C@M/GCE sensor can detect p-nitrotoluene (p-NT) with good sensitivity, reproducibility, repeatability and long service life, and a very low detection limit (0.485 nM) of p-NT was obtained, it also can simultaneously detect p-nitrophenol (p-NP), o-nitrophenol (o-NP) and p-NT with reliable sensitivity and no interference. This investigation offered a useful method for successful β-CD electropolymerization on tubes of MWCNTs-COOH for further applications, it also provided an ideal electrochemical platform for simultaneous detection of multiple nitro-aromatic compounds.

Keywords: electropolymerization, electrochemical sensing, nitro-aromatic compounds, β-cyclodextrin, simultaneous detection