Toward Precision in Biomarker Analysis: A Novel Malondialdehyde Detection Method Based on Molecularly Imprinted Polymers.

Malondialdehyde (MDA) is a critical biomarker of oxidative stress, playing a significant role in diagnosing and monitoring conditions associated with oxidative damage, including cardiovascular diseases, neurodegenerative disorders, and cancer. This study reports the synthesis and application of a molecularly imprinted polymer (MIP)-based electrochemical sensor for MDA detection using a dual biopolymer chitosan/κ-carrageenan matrix integrated with Fe3O4 nanoparticles on a boron-doped diamond (BDD) electrode. Differential pulse voltammetry (DPV) was employed to evaluate analyte recognition, while FTIR, DLS, SEM, EIS, and cyclic voltammetry were used for sensor characterization. Under optimized conditions (75% chitosan, 25% κ-carrageenan, and 10 mg Fe3O4 nanoparticles), the sensor exhibited high sensitivity (687.35 μA/μM), a low detection limit (0.005 μM), and a linear detection range of 0.026-0.26 μM. The developed platform also demonstrated good reproducibility, repeatability, and selectivity toward MDA in the presence of common interfering compounds. Analytical performance was further validated in spiked water and artificial serum samples, showing satisfactory recovery values. The proposed sensor outperformed several previously reported MDA sensing platforms, highlighting its potential as a sensitive and reliable tool for oxidative stress biomarker detection and future clinical applications.