Investigation of kinetic parameters of chloramphenicol and its conjugates’ interaction with monoclonal antibodies using label-free biosensors based on low-coherence interferometry

Introduction

Chloramphenicol (CAP) is a widely used antibiotic in veterinary medicine, posing a risk of contamination in animal-derived food products. Detecting CAP is crucial due to its potential health hazards, such as allergic reactions and antibiotic resistance. Immunoanalytical test systems based on monoclonal antibodies (mAbs) are commonly used to detect CAP. However, most studies focus on mAb interactions with CAP-conjugates, while the kinetics of interactions with free CAP remain poorly understood. Our study addresses this gap, for the first time evaluating the kinetic parameters of mAbs binding to both CAP-conjugates and free CAP. This dual characterization is essential for designing more effective detection systems.

Materials and Methods

To achieve this, we used a label-free biosensor system based on low-coherence interferometry. Carboxylated glass chips immobilized with bovine serum albumine (BSA-CAP) conjugates served as the sensor surface. The interactions of the sensor with monoclonal antibodies and mixtures of antibodies with free CAP were analyzed. A tailored kinetic model was applied to calculate dissociation constants and evaluate the binding dynamics.

Results and Discussion

Our results reveal the kinetic parameters for mAb interactions with both BSA-CAP conjugates and free CAP. The dissociation constants and binding dynamics provide critical insights into the affinity and specificity of mAbs under different conditions. This approach demonstrates the system's capacity to differentiate interactions with conjugated and free CAP, showcasing its applicability in developing precise and reliable CAP detection methods.

Conclusions

This study establishes a novel methodology for characterizing mAb interactions with free CAP alongside conjugated forms. By leveraging a low-coherence interferometry-based biosensor, the findings contribute to the creation of advanced, high-sensitivity detection systems for CAP, ultimately enhancing food safety monitoring.­­­­­