2. Academic Validation
  3. Discrimination of the S-isomer of ofloxacin using nanozyme-enhanced immunochromatographic analysis based on a secondary antibody-modified Au@Pd nanozyme

Discrimination of the S-isomer of ofloxacin using nanozyme-enhanced immunochromatographic analysis based on a secondary antibody-modified Au@Pd nanozyme

  • Mikrochim Acta. 2026 Jun 8;193(7):460. doi: 10.1007/s00604-026-08172-7.
Olga D Hendrickson 1,  Nadezhda A Byzova 2,  Vasily G Panferov 2,  Elena A Zvereva 2,  Taisiya V Ivanova 3,  Shen Xing 4,  Anatoly V Zherdev 2,  Hongtao Lei 4,  Boris B Dzantiev 2
Affiliations

Affiliations

  • 1 A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, Moscow, 119071, Russia. [email protected].
  • 2 A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, Moscow, 119071, Russia.
  • 3 Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Leninsky Prospect 31, Moscow, 119071, Russia.
  • 4 Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
PMID: 42258022 DOI: 10.1007/s00604-026-08172-7
Abstract

Ofloxacin, a fluoroquinolone Antibiotic, is a significant contaminant in food products. Its levorotatory form (S-OFL) exhibits a bactericidal activity considerably higher than the dextrorotatory form (R-OFL) and is commonly employed in veterinary medicines. In this work, a highly sensitive immunochromatographic analysis (ICA) method for biologically active S-OFL was developed. A bimetallic core@shell Au@Pd nanozyme was synthesized to serve as the label. Thanks to its peroxidase-like catalytic activity, the nanozyme enhances the color signal on test strips, thereby improving assay sensitivity. The instrumental limit of detection and cutoff values were determined to be 1.4 pg/mL and 0.1 ng/mL, corresponding to 60- and 10-fold improvements compared with conventional gold nanoparticle-based ICA. The cross-reactivity with R-OFL was only 6.3%, demonstrating the high specificity toward target isomer. The ICA was successfully applied to detecting S-OFL in milk, achieving recoveries of 77-99%. The entire nanozyme-enhanced analysis can be completed within 20 min. This method shows potential for monitoring various toxicants in food products.

Keywords

Antibiotic detection; Au@Pd nanozyme; Catalytic enhancement; Fluoroquinolone; Food safety; Immunochromatographic analysis; S-ofloxacin.

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