Photoelectronic characterization of IgG antibody molecule–quantum dot hybrid asbiosensing probe

Abstract

Quantum dot (QD)-based biomolecule hybrids have recently attracted much attention inspecifically identifying and labeling target proteins. In this study, QD encapsulated withimmunoglobulin antibodies, as a labeling building block in biosensors, was investigated toclarify the most efficient configuration and photoluminescence behavior. Boththe biological recognition capacity and photoluminescence emitting signal of theantibody-coupled nanocrystal were validated through a photoelectrical characterizationprocedure. Derivation of the optimum number of antibody molecules to be packedonto the QD surface yielded the highest binding capacity for the target antigen.During formation of the bioactive layer, the intrinsic photoluminescence responseof the QDs significantly decreased due to photoinduced hole transfer accordingto their rearranged electronic structure. The thorough study of this assemblyprovides a validation approach for the careful titration of biosensor probes foroptimal reaction kinetics. Furthermore, it contributes to the development of aneffective tool for the application and interpretation of QD-based labeling techniques.