Electrochemical Detection of Gallic Acid in Green Tea Using Molecularly Imprinted Polymers on TiO2@CNTs Nanocomposite Modified Glassy Carbon Electrode
Fengxian Qin, Tiejun Hu, Lixin You, Wei Chen, Dongshu Jia, Nannan Hu, Weihua Qi
Abstract
The purpose of this study was to use molecularly imprinted polymers on a TiO 2 @CNTs nanocomposite modified glassy carbon electrode (MIP/TiO 2 @CNTs/GCE) to electrochemically determine gallic acid (GA) in green tea. The TiO 2 @CNTs nanocomposite was used to modify the GCE surface using the electrodeposition method and MIP was electropolymerized on the nanocomposite modified GCE. The successful electrodeposition of TiO 2 @CNTs nanocommposite on GCE and the electropolymerization of the MIP layer on the nanocommposite surface were demonstrated by structural investigations using SEM and XRD. The MIP/TiO2@CNTs/GCE was found to be a stable and selective GA electrochemical sensor with a concentration range of 50–700 μM, a sensitivity of 0.02348μA/μM, and a limit of detection (LOD) of 12 nM in electrochemical tests employing DPV experiments. A comparison of the performance of MIP/TiO 2 @CNTs/GCE with that of existing GA electrochemical sensors revealed that the suggested sensor had improved performance, a larger linear range, and an acceptable LOD value for GA detection. The precision and applicability of the proposed electrochemical GA sensor were investigated for determining the level of GA in a prepared real sample of green tea, and the results showed that RSD (2.86% to 4.20%) and recovery (97.65% to 99.30%) of spiked levels in a prepared real sample were acceptable, indicating that MIP/TiO 2 @CNTs/GCE can be considered a reliable GA sensor in food samples.