A novel hybrid carbon materials-modified electrochemical sensor used for detection of gallic acid

Novel hybrid carbon materials such as activated carbon-carbon nanotubes (AC-CNTs) and carbon spheres/activated carbon-carbon nanotubes (CSs/AC-CNTs) based on activated carbon (AC) derived from the pits of Algerian date palm have been prepared and characterized. In addition, the carbon paste electrodes based on graphite carbon (GC) and cavity microelectrode (CME) modified with these hybrid materials were used to detect gallic acid at pH = 7 using square wave voltammetry method (SWV). The conductivity measurements revealed that CSs/AC-CNTs is more conducting than AC-CNTs. SWV measurements showed that the oxidation current was directly proportional to the concentrations of gallic acid (from 0 to 0.00536 M) with the lowest limit of detection (LOD), reaching 6.43 mu M and 3.64 mu M using GC/CSs/AC-CNTs electrode and CME/GC/CSs/AC-CNTs sensor, respectively. The reproducibility and the stability of the studied sensor were confirmed by the relative standard deviation of the oxidation current response of gallic acid (RSD (Reproducibility) = 1.44% and RSD (Stability) = 3.7%).

Automated summary

Novel hybrid carbon materials based on activated carbon from Algerian date palm pits were prepared and characterized, with carbon paste electrodes modified with these materials successfully detecting gallic acid using square wave voltammetry. The conductivity of the materials was compared, showing CSs/AC-CNTs to be more conductive than AC-CNTs. The oxidation current of gallic acid was found to be directly proportional to its concentration, with GC/CSs/AC-CNTs electrode and CME/GC/CSs/AC-CNTs sensor achieving low limits of detection. The reproducibility and stability of the sensor were confirmed by the relative standard deviation of the gallic acid oxidation current response.