Construction and Application of A Novel N-G-Based MIES for Highly Sensitive Recognition and Rapid Detection of Cinnamaldehyde

Cinnamaldehyde, the principal bioactive compound responsible for cinnamon’s antimicrobial, anti-inflammatory, and antidiabetic properties, serves as a critical quality indicator for cinnamon and its derivatives. Currently, the rapid detection of cinnamaldehyde is limited by the lack of methods that provide both high sensitivity and the ability to avoid sample pretreatment. In this study, a molecularly imprinted electrochemical sensor (MIES) was developed via in situ polymerization of methacrylic acid (MAA) around cinnamaldehyde templates on nitrogen-doped graphene (N-G)-modified electrodes. The N-G material synergistically enhanced the sensor’s sensitivity by expanding the electrochemically active surface area and accelerating electron transfer, while the molecularly imprinted membrane ensured selectivity through cinnamaldehyde-specific recognition cavities. The sensor demonstrated a broad linear range (0.1 to 10³ ng ml⁻¹), a low detection limit (5.3 × 10^–2 ng ml⁻¹, S/N = 3), and outstanding reproducibility and stability. This research offers an economical and reliable method for on-site cinnamaldehyde detection and establishes a pioneering approach for rapid quality assessment of traditional Chinese medicine and associated formulations.