A Biomimetic Electrochemical Approach for Chlorogenic Acid Detection in Herbal Supplements and Plant Extracts Using...

In this work, a novel molecularly imprinted polymer (MIP)-based electrochemical sensor was designed for the selective detection of chlorogenic acid (CGA), with the MIPs synthesized through a photopolymerization strategy employing 2-thienylboronic acid (2-TBA) as the functional monomer, thereby creating highly specific recognition sites capable of selectively binding CGA molecules within complex sample matrices. The applicability of the proposed MIP-based sensor was demonstrated by electrochemical detection of CGA in authentic samples of several Asyneuma species, including Asyneuma limonifolium and Asyneuma linifolium subspecies, indicating its potential for use in plant extract and herbal supplement analysis. A comprehensive evaluation of the CGA/2-TBA@MIP-GCE sensor was conducted to elucidate its morphological features and electrochemical characteristics, providing detailed insights into surface topography, electron-transfer kinetics, and overall sensor responsiveness. The analysis revealed that the imprinted polymer matrix exhibited highly organized recognition sites and efficient charge-transport pathways. For indirect CGA determination using 5.0 mM [Fe-(CN)₆]^3-/^4- as the redox probe, linearity was observed between 2.5 × 10^-13 and 1.75 × 10^-12 M. Based on the standard calibration data, the sensor exhibited an extremely high sensitivity, with a limit of detection (LOD) calculated at 2.34 × 10^-14 M and a limit of quantification (LOQ) of 7.79 × 10^-14 M. These results highlight the sensor's remarkable ability to detect even trace amounts of CGA with precision and reliability. The developed electrochemical sensor based on molecularly imprinted polymers showed remarkable selectivity and sensitivity toward CGA, highlighting its robust molecular recognition properties. Furthermore, comprehensive recovery analyses were conducted to evaluate the platform's practical applicability in real sample matrices, and the obtained recovery values were within acceptable analytical ranges. These results collectively indicate that the proposed sensor system functions as a robust, reliable, and analytically sensitive platform for the quantitative determination of CGA.