Protein-Enhanced Photoelectrochemical Sensor for Antioxidant Detection in Biodiesel Using Zinc Vanadate and...

Biodiesel stability is vital for performance, storage, and environmental benefits. However, oxidation and degradation can reduce its quality, leading to engine issues and reduced efficiency. Antioxidants are crucial to prevent these problems, but their detection remains a challenge. This study introduces a photoelectrochemical (PEC) sensor for detecting the 2-(1,1-dimethylethyl)-1,4-benzenediol (DBD) antioxidant in biodiesel. The sensor, constructed with FTO electrodes modified with sulfur-doped graphitic carbon nitride (g-C₃N₄-S), zinc vanadate (Zn₃V₂O₈), and the protein cytochrome C (Cyt-c), showed a significantly higher PEC response compared to individual materials. Cyt-c enhances the photocurrent generation by reducing the recombination of photogenerated charges on the PEC platform surface. Photocurrent measurements were performed using amperometry with a 36 W white LED lamp as the irradiation source. Under optimized conditions, the sensor demonstrated two linear detection ranges: 0.6 to 160 and 160 to 2000 μmol L^-1. The sensor was successfully applied to biodiesel samples, achieving recovery values between 98.99 and 105.26%, highlighting its accuracy and reliability for practical applications. This innovative approach addresses the challenges of detecting antioxidants in biodiesel, offering a sophisticated yet highly efficient solution to ensure fuel quality.