Electrochemical Sensor for Highly Sensitive Detection of Gallic Acid Based on Graphitized and Carboxylated Multi-Walled Carbon Nanotubes modified Glassy Carbon Electrode

Abstract

Herein, we used the graphitized and carboxylated multi-walled carbon nanotubes (GCMCNTs) to decorate the glass carbon electrode (GCE), which was employed to construct the GCMCNTs/GCE sensor for the detection of GA. GCMCNTs with one-dimensional nanotube-like structure exhibited high specific surface area and excellent electrical conductivity. GCMCNTs with high graphitization degree and carboxylation groups provided more microsites for electrochemical reaction and highly efficient electron transport channels, which helped promote the electron transmission and enhance the dispersibility of carbon material. The GCMCNTs/GCE sensor achieved the sensitive electrochemical determination of GA. The fabricated sensor presented a quite low limit of detection of 0.0032 μM (S/N=3) with the corresponding linear equation of Ip (μA) =21.506C+3.134 (R2=0.995) in the linear GA concentration range of 0.01-10 μM. In addition, the good GA detection could be realized in the tap water sample.