Integrated biomolecule-quantum dot hybrid systems for bioanalytical applications

Recent scientific efforts are directed to the coupling of biomolecules with semiconductor quantum dots (QDs) to yield hybrid nanomaterials. The biomolecule/QDs conjugates combine the unique optical and electrical properties of QDs with the recognition and catalytic functions of biomolecules and provide new materials for versatile bioanalytical applications. The article addresses different approaches that implement functional biomolecule-QD hybrid systems for sensing applications. QDs are implemented as fluorescent labels for biorecognition events, and the size-controlled luminescence features of QDs are used for the development of multiplexed analysis schemes. Also, fluorescence resonance energy transfer (FRET), electron transfer, and chemiluminescence resonance energy transfer (CRET) processes are used to probe the dynamics of biorecognition events and biocatalyzed transformations. Specifically, the incorporation of functional QDs into cells holds great promise for monitoring intracellular metabolic pathways and for future applications in nanomedicine. Finally, photocurrents stimulated by QDs linked to electrodes are used to transduce biorecognition events and biocatalytic processes.