Development of portable and highly sensitive electrochemical sensor for rapid on-site analysis of levofloxacin residue in pork samples

Levofloxacin is widely utilized as a livestock feed additive, yet its residues in animal-derived foods pose risks to human health. Herein, a portable and highly sensitive electrochemical sensor was developed for on-site levofloxacin detection in food of animal origin. The sensor employs facile electrochemical polymerization of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) on electrodes, leveraging its dual recognition: hydrophobic cavities form complexes with levofloxacin, while hydroxypropyl groups enable hydrogen bonding to enhance the specificity. The optimized parameters endowed the sensors with a low limit of detection (0.52 ng·mL^-1 for HP-β-CD/GCE and 0.16 ng·mL^-1 for HP-β-CD/SPE), a wide linear range (0.0075-10.0 μg·mL^-1), excellent selectivity and good matrix resistance. A portable sensor platform based on HP-β-CD/SPE, mini workstation and smartphone was then constructed to detect trace levofloxacin in pork samples. This platform is with the merits of high sensitivity, portability and on-site analysis ability, offering a promising approach for rapid on-site antibiotic residue analysis in foods.