Development of electrochemical sensor for vanillin determination using carbon spheres-LaFe_0.9Ni_0.1O₃ nanohybrid

Vanillin is widely used in the confectionery and pharmaceutical industries due to its unique aroma, flavor, antioxidant, and antimicrobial properties. However, excessive consumption leads to adverse important effects such as headaches, nausea, vomiting, and impaired liverier and kidney function. Here, an electrochemical sensor based on LaFe_0.9Ni_0.1O₃ nanoparticles functionalized with carbon spheres (C-LFNO) is designed for the determination of vanillin in food samples. The structural characteristics of C-LFNO nanohybrid were investigated using X-ray diffraction, Fourier-transform infrared spectroscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The objective of this study was to develop a sensor with a low limit of detection (LOD) and high sensitivity for rapid and accurate determination of vanillin using amperometry. The sensor exhibited a linear detection range from 0.008 to 0.36 μM as well as LOD and limit of quantification of 0.011 and 0.035 μM, respectively. Additionally, the recovery of vanillin in real food samples, including ice cream and chocolate at different matrix ratios (25, 50, and 70%), ranged from approximately 87 to 104%, with relative standard deviation values between 2.17 and 4.72%, demonstrating the sensor's good accuracy and precision in complex sample matrices.