A Novel Molecularly Imprinted 4-Vinyl Pyridine Electrode for Detection and Quantification of Cinnamic Acid in Food Samples

Cinnamic acid (CA) is a key intermediate in the biosynthesis of various plant metabolites and is widely present in food products such as tea, cinnamon, and fruits. It also possesses several pharmacological benefits, including antioxidant, anti-inflammatory, antibacterial, and anticancer properties. However, excessive or unregulated intake of CA can have adverse health effects, necessitating precise and reliable detection methods. In this study, a 4-Vinyl Pyridine polymerized graphite electrode (4-VP@G) has been fabricated to detect and quantify the Cinnamic acid (CA) in black tea and cinnamon powder samples. The molecularly imprinted polymer (MIP) material was synthesized using 4-Vinyl Pyridine (4-VP) as the monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker in graphite bed. The synthesized material was characterized using Ultra Violet-Visible (UV-Vis) spectroscopy and scanning electron microscopy (SEM) techniques. The analytical performance of the fabricated electrode was evaluated by 3-electrode configuration using cyclic voltammetry (CV) as well as differential pulse voltammetry (DPV). The fabricated electrode (4-VP@G) has shown a wide range of linearity from 1 μM to 1000 μM with a limit of detection (LOD) of 8.2 nM. The electrode shows satisfactory repeatability, reproducibility and stability properties with relative standard deviation (RSD) values of 1.01%, 1.14% and 1.013%, respectively. Furthermore, to assess the performance of the developed electrode in real samples- three black tea and two cinnamon powder samples were experimented. To detect CA in comparison with the high-performance liquid chromatography (HPLC), the MIP electrode showed satisfactory results (94% ~ 98%) when used with real samples. Moreover, from the t-test, calculated statistical data were satisfactory for CA concentration present in real samples.