Electro-fluorescence gel-based sensing miniaturized approach for screening and determination of norfloxacin at trace level in milk and egg samples: A green strategy for food analysis.

In this study, a hybrid method using fluorescence image detection and IG-EME (In-Gel Electromembrane Extraction) is developed to extract and detect norfloxacin, a quinolone antibiotic with intrinsic fluorescence properties. The developed novel hybrid technique, Fluorescence-In-Gel Electromembrane Extraction (FL-IG-EME), was evaluated by extracting and detecting norfloxacin in milk and egg samples, demonstrating its potential for sensitive and selective analysis. Under optimized experimental conditions, the method achieved a LOQ of 3.0 μg L, which is well below the maximum residue limit of 1.0 mg L established for the quinolones in animal products. The FL-IG-EME technique offered rapid and effective extraction (within 5 min) simultaneously with preconcentration in one step. A smartphone application that demonstrated good agreement with ImageJ results was developed to streamline the process of image capture and analysis. The developed technique adheres to green chemistry principles, providing a sustainable and environmentally friendly approach for antibiotic detection in food safety applications.