NaCl-induced Gold Nanoparticles colorimetric sensor based on boronate affinity-oriented molecular imprinting recognition of antibiotics kanamycin in fish pond

The development of highly specific rapid detection method for antibiotics residue was critically imperative in complex environmental samples was due to its environmental and health risk. Here, a highly specific biomimetic Fe 3 O 4 @SiO 2 -formylphenylboronic acid molecular imprinted polymer (FS-FPBA MIP) was constructed, which was coupled with gold nanoparticle-based colorimetric sensor, for rapid detection of antibiotics Kanamycin (Kana) in fish pond. Firstly, a boronate affinity-controlled oriented surface imprinting strategy was employed to immobilize Kana as the template molecule onto a Fe 3 O 4 @SiO 2 substrate functionalized with boronic acid, resulting in a MIP layer with a well-defined thickness. Subsequently, when NaCl and Kana sample were added to gold nanoparticles (AuNPs), the FS-FPBA MIP specifically recognized Kana. Accordingly, the color of AuNPs solution quickly changed from wine red to dark blue due to charge shielding and charge neutralization effects. By taking a photo with a smartphone and using the software “Color Identifier” to read the RGB data, a rapid visual detection of Kana was achieved. The FS-FPBA MIP-colorimetric sensor exhibited a desirable linear response for Kana in the concentration range of 0-150   nM, with a low detection limit of 4.3   nM (3 σ / k ). Finally, the magnetic FS-FPBA MIP was successfully applied for selective extraction and colorimetric detection of different Kana samples in pond water, sediment, and surrounding soil with the relative recoveries ranging from 90.03% to 104.53%. This highly specific enrichment and visual sensor offered a promising biomimetic recognition platform for rapid detecting antibiotic residues.