Functional Up-Conversion Nanoparticle-Based Immunochromatography Assay for Simultaneous and Sensitive Detection of Residues of Four Tetracycline Antibiotics in Milk.

Ying Xu,Erjing Chen,Biao Ma,Chuanxin Sun,Mingzhou Zhang,Xiaoping Yu

doi:10.3389/fchem.2020.00759

Abstract

An ultrahigh-sensitivity lateral flow immunochromatography (LFIC) assay based on up-converting nanoparticles (UCNPs) was developed to carry out a multi-residue detection of tetracycline in milk. The sensitivity of the immunoassay was greatly improved by the use of a broad-spectrum monoclonal antibody attached to UCNPs to form a signal probe. Under the optimal conditions, the UCNP-LFIC assay enabled sensitive detection of tetracycline (TC) as well as of oxytetracycline (OTC), chlortetracycline (CTC), and doxycycline (DOX) within 10 min, with IC50 values of 0.32, 0.32, 0.26, 0.22 ng/mL, respectively. There was no cross-reactivity with ten other antibiotics. Similarly, we evaluated the experimental results for matrix effects. Experiments involving spiking showed the four tetracycline antibiotics displaying mean recoveries ranging from 93.95 to 111.90% with relative standard deviations (RSDs) of < 9.95%. The detection results of actual samples using the developed method showed a good correlation (R2 ≥ 0.98) with the results using high-performance liquid chromatography (HPLC). Thus, the assay can achieve an ultrahighly sensitive detection of antibiotics in milk, and can hence promote human health and provides promising applications in the bio-detection field.

Highlights

As antibacterial pharmaceuticals, antibiotics have been widely used to treat bacterial infections in humans and animals (Han et al, 2015; Dubald et al, 2018)
The detection of up-converting nanoparticles (UCNPs)-lateral flow immunochromatography (LFIC) was based on the principle of a competitive reaction
The immobilized antigen competed with the target analyte in the sample solution for the UCNP-mAb probe

Summary

Introduction

Antibiotics have been widely used to treat bacterial infections in humans and animals (Han et al, 2015; Dubald et al, 2018). Β-lactams, tetracycline (TC) and streptomycin are the most commonly used antibiotics for the treatment of cow mastitis (Zhou et al, 2018). As a broad-spectrum antibiotic, tetracycline has antibacterial effects and shows widespread use in milk (Xie et al, 2018). Overuse of this antibiotic may cause gastrointestinal tract problems such as nausea and vomiting and can be toxic to the liver and cause kidney damage, allergic reactions, etc. L. et al, 2015; Yang et al, 2017). In this regard, the United States, the European Union and other countries have stipulated the maximum residue limits (MRLs) of tetracyclines

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Results

Conclusion