Preparation of cassava fiber-iron nanoparticles composite for electrochemical determination of tea polyphenol

Rapid detection of tea polyphenol is necessary in food and beverages. In this work, we used cassava fibers as a substrate on which iron nanoparticles were immobilized. The proposed composite was used for surface modification of glassy carbon electrodes to prepare an electrochemical sensor for the detection of tea polyphenols. The SEM characterization results show that the iron nanoparticles on the surface of the cassava fibers were distributed uniformly. We investigated the electrochemical behavior of tea polyphenols on the surface of modified electrodes. The result indicated that the iron nanoparticles could facilitate the electron transfer rate and subsequently enhance the sensing performance. Meanwhile, we have optimized the detection parameters. The proposed sensor can linearly increase the peak current of tea polyphenol oxidation in the range of 3.5–31.5 µM with a equation of I (µA) = 0.01285c + 0.89734 (r = 0.9958). The detection limit can be calculated to be 0.1 µM. In addition, we have validated the proposed sensors in real samples. The results demonstrate that this sensor can be potentially used for the detection of tea polyphenols in beverages.