Development and Validation of a Reproducible and Label-Free Surface Plasmon Resonance Immunosensor for Enrofloxacin Detection in Animal-Derived Foods

Abstract

This study describes the development of a reproducible and label-free surface plasmon resonance (SPR) immunosensor and its application in the detection of harmful enrofloxacin (ENRO) in animal-derived foods. The experimental parameters for the immunosensor construction and regeneration, including the pH value (4.5), concentration for coating ENRO-ovalbumin conjugate (ENRO-OVA) (100 μg·mL−1), concentration of anti-ENRO antibody (80 nM) and regeneration solution (0.1 mol·L−1 HCl) were evaluated in detail. With the optimized parameters, the proposed SPR immunosensor obtained a good linear response to ENRO with high sensitivity (IC50: 3.8 ng·mL−1) and low detection limit (IC15: 1.2 ng·mL−1). The proposed SPR immunosensor was further validated to have favorable performances for ENRO residue detection in typical animal-derived foods after a simple matrix pretreatment procedure, as well as acceptable accuracy (recovery: 84.3–96.6%), precision (relative standard deviation (n = 3): 1.8–4.6%), and sensitivity (IC15 ≤ 8.4 ng·mL−1). Each SPR chip for analysis can be reused at least 100 times with good stability and the analysis cycle containing the steps of sample uploading/chip regeneration/baseline recovery can be completed within 6 min (one cycle) and auto-operated by a predetermined program. These results demonstrated that the proposed SPR immunosensor provided an effective strategy for accurate, sensitive, and rapid detection for ENRO residue, which has great potential for routine analysis of large numbers of samples for measuring different types of compounds.

Affinity-Based Analysis Methods for the Detection of Aminoglycoside Antibiotic Residues in Animal-Derived Foods: A Review

“…It has attracted wide attention because of its simple structure, flexible application, convenient use and the amenability of integration into multi-functional analysis [ 106 , 107 , 108 ]. In addition, specific recognition provides the unique selectivity and high sensitivity for the sensor [ 109 ], which makes it gradually applied to the fields of food safety control [ 110 , 111 , 112 , 113 , 114 ], environmental monitoring [ 115 , 116 , 117 ] and medical diagnosis [ 118 , 119 , 120 ].…”

Optical Biosensors for Label-Free Detection of Small Molecules

“…The competitive inhibition assay with a monoclonal antibody that cross-reacts with NIV and DON provided IC 50 values of 28.8 and 14.9 ng/mL for NIV and DON, respectively [73]. Likewise, SPR immunosensors with BSA-conjugated domoic acid (DA) and cortisol were used to analyze DA contamination in clam extracts [74] or cortisol levels in saliva [75], respectively, whereas others have reported sensors with ovalbumin (OVA)-conjugated enrofloxacin (ENRO) [76] as well as patulin [77] and benzylpenicillin [78] conjugated to glutamine-binding protein for target immobilization. Alternatively, protein-conjugated small molecules have been immobilized on a sensor surface using self-assembled monolayers (SAMs) to obtain good stability high degree of reproducibility.…”

A highly sensitive lateral flow immunoassay for the rapid and on-site detection of enrofloxacin in milk

“…For instance, Terrado-Campos et al detected ENR in porcine and bovine meat using high-performance liquid chromatography ( 11 ). Other conventional techniques such as capillary electrophoresis ( 12 ), mass spectrometry ( 13 , 14 ), surface plasmon resonance ( 15 ), surface-enhanced Raman scattering ( 16 ), and matrix solid-phase dispersion ( 17 ). Although these tools possess high sensitivity, selectivity, and appreciable accuracy, still, they require ultrafine chemicals, sophisticated maintenance, and professional and well-trained technicians.…”