Selective Detection of Food-Adulterant 4-Methylimidazole Using Synthetic Receptor-Functionalized Reflective Heterofiber Structure

Adulteration of different harmful chemicals into food products is a global issue that threatens food safety and public health. The consumption of contaminated food causes serious health problems and acute food poisoning. Therefore, the detection and monitoring of food quality have become very important health aspects for regulatory authorities and consumers. Here, we report a fiber optic interferometry-based biosensor for selective detection of toxic food adulterant 4-methylimidazole (4-MeI). The sensor comprises a photonic crystal fiber (PCF)-based single-ended transducer, functionalized with a synthetic receptor. The sensor shows a wide dynamic detection range with high sensitivity and a repeatable detection performance. It holds the potential of measurement up to 3 ng/L concentration of 4-MeI and a remarkable detection specificity independent of different interfering elements. The compact structure, simple measurement, high sensitivity, repeatable nature, and wide operating range of this sensor would provide a way for the development of biochemical sensors in commercial application fields, including pharmaceutical, agricultural, and food processing industries.