Wireless portable intelligent nanosensor for pretreatment-free, anti-interference, and real-time on-site detection of furazolidone in fish products

Furazolidone (FZD) is a banned antibiotic in food-producing animals due to its carcinogenicity and toxicity. Its illegal use and residue persistence in foods remains a health risk, highlighting the need for a rapid and reliable detection. Electrochemical sensing offers rapidity and sensitivity; however, its use is limited by bulky instrumentation and low accuracy in complex food matrices, making on-site testing difficult. To overcome these limitations, this work developed a wireless portable intelligent nanosensor for direct, pretreatment-free detection of FZD in food. The nanosensor features a mesoporous silicon film microelectrode (MSFM) with nanopores, which significantly enhances selectivity through size exclusion, electrostatic repulsion, hydrophilic interaction, and nanoscale confinement effects. Integrated with a smartphone via Bluetooth, the nanosensor allows immediate visualization of detection results. Under optimized conditions, the nanosensor can directly detect trace amounts of FZD in fish samples in real time without the need for enrichment or preprocessing. It exhibited a wide linear range from 0.1 to 100.0 μmol/L and a detection limit of 0.05034 μmol/L, with excellent anti-fouling ability, reproducibility (RSD 4.50 %), and 15-day signal stability. This innovative wireless sensing technology holds great promise for extending laboratory-based detection techniques to on-site and market environments, particularly in resource-constrained areas.