Sulfur-inspired layered g-C3N4-incorporated NiFe2S4 nanocomposite for electrochemical and real-time detection of vanillin in food samples

Background

Vanillin is a widely used flavoring agent and plays a crucial role in food safety, making its accurate detection essential. Developing sensitive and cost-effective methods for vanillin detection is vital for ensuring food quality and consumer protection.

Methods

This study introduces a novel sulfur-engineered g-C₃N₄/NiFe₂S₄ nanocomposite synthesized via a simple and scalable method. The composite was employed to modify a glassy carbon electrode (GCE), significantly improving its electrochemical properties. Structural and morphological characterizations confirmed the successful integration of g-C₃N₄ with NiFe₂S₄. Differential pulse voltammetry (DPV) was conducted under optimized conditions (pH 7).

Significant Findings

The modified GCE exhibited a substantially enhanced oxidation peak current for vanillin, indicating superior electrocatalytic activity. The sensor achieved a wide linear detection range (0.01 - 360 µmol l^-1), a low detection limit (0.00031 µmol l^-1), and excellent selectivity, stability, repeatability, and reproducibility. Uniquely, the synergy between g-C₃N₄ and NiFe₂S₄ provided enhanced charge transfer and surface activity. Application of the sensor to real food samples including ice cream, wafers, and coffee demonstrated accurate recovery and practical feasibility, underscoring its potential as a reliable tool for food safety monitoring in real-world scenarios.