Interfacial engineering of VS/TiCT MXene heterojunctions for portable electrochemical sensing of nitrofurantoin residues in food and water samples.

The contamination of nitrofurantoin (NFT) antibiotics in the food chain poses significant threats to environmental and public health, emphasizing the urgent need for rapid and portable detection. This study presents an electrochemical sensor based on a 2D/2D van der Waals heterojunction of VS and TiCT MXene integrated onto a screen-printed carbon electrode (SPCE). Interfacial engineering of TiS bonds creates efficient charge transfer pathways and a directional built-in electric field, enhancing charge dynamics and electroreduction efficiency. The VS/TiCT MXene-SPCE sensor shows an ultralow detection limit of 4.7 nM, a wide linear range (0.01-400 μM), and high stability with strong resistance to interference. Its practical applicability was validated by successful NFT detection in tap water, lake water, milk, and honey, yielding satisfactory results. This work highlights the catalytic potential of VS/ TiCT MXene heterojunctions and demonstrates the sensor as a promising tool for environmental monitoring and food safety.