An Electrochemical Sensor Based on 3D Graphene-Cyclodextrin Nanohybrid for Enhanced Sensitivity Detection of Nitroaromatic Compounds

Abstract

This study presents an electrochemical sensor for sensitive detection of nitroaromatic compounds using a three-dimensional (3D) porous graphene with polyoxypropylene supported reduced graphene oxide (PEA-RGO) and embedded β-cyclodextrins (β-CD). First, PEA-RGO was synthesized by the condensation reaction between graphene oxide (GO) and amino-terminated polyoxypropylene (PEA), followed by hydrazine hydrate reduction. Then, β-CD was embedded into the porous of the above 3D graphene to obtain PEA-RGO/β-CD nanohybrid. Various characterization techniques, such as microscopy imaging, infrared spectrometry, thermal analysis and electrochemical measurements, were employed to confirm the successful synthesis and unique 3D architecture structure of PEA-RGO/β-CD. Afterwards, the glassy carbon electrode (GCE) was modified by PEA-RGO/β-CD, and its electrochemical detection performances were investigated for detecting nitroaromatic compounds, including nitrobenzene (NB), 2-nitroaniline (2-NA), 2-chloronitrobenzene (2-NCB), and 2-nitrophenol (2-NP). The results of electrochemical measurements exhibited relative higher sensitivities (1.88 μA/μM/cm² for NB, 2.13 μA/μM/cm² for 2-NA, 2.35 μA/μM/cm² for 2-NP, 0.83 μA/μM/cm² for 2-NCB, respectively) and lower limits of detection (LOD) (39.4 nM for NB, 44.6 nM for 2-NA, 75.6 nM for 2-NP, 69.6 nM for 2-NCB, respectively). Additionally, the proposed sensor was also applied in detection in real samples with recovery range of 88.13%–109.52 %. The enhanced detecting performances can be attributed to the synergistic effect of the high conductivity from RGO, recognition capabilities from β-CD, and excellent properties from 3D structure. The present work would provide a robust tool for environmental monitoring and the detection of nitroaromatic pollutants.