Resonance energy transfer in hydrogels based on quantum dots and capture antibodies: A prototype nanophotonic immunodiagnostic system

In recent years, a growing number of studies have investigated the structural and optical properties of hydrogels based on various nanoparticles. Due to their high porosity and compatibility with living tissues, hydrogels provide a promising basis for the development of sensitive and specific biomolecule detectors (biosensors). This study has estimated the efficiency of Förster resonance energy transfer (FRET) in hydrogel systems containing CdSe/ZnS quantum dots, diamine derivatives of polyethylene glycol (PEG) with different molecular weights, and immunoglobulin molecules labeled with the AlexaFluor 633 fluorophore. The new system is a prototype nanophotonic diagnostic tool where immunoglobulins labeled with organic fluorophores serve as “identification tags” for detecting disease biomarkers. It has been shown that FRET occurs in this prototype between hydrogel quantum dots (energy donors) and AlexaFluor 633 fluorophores (energy acceptors) with an efficiency as high as 87%. The results demonstrate that the hydrogels based on quantum dots and diamine derivatives of PEG developed here can be used for highly sensitive and specific FRET-based immunohistochemical analysis of biomarkers providing a high signal-to-background ratio.