Fluorescence Resonance Energy Transfer between Quantum Dots and Graphene Oxide for Sensing Biomolecules

TLDR

The authors designed a novel FRET‑based platform using quantum dots and graphene oxide for sensitive biomolecule sensing. Quantum dots were functionalized with a molecular beacon that quenches fluorescence upon binding to graphene oxide; target binding increases the beacon–GO distance, attenuates FRET, and restores QD fluorescence. The resulting fluorescence change enabled detection of DNA sequences and proteins with high sensitivity, specificity, and low probe synthesis effort, marking the first use of QD–GO FRET for biorecognition.

Abstract

This work designed a novel platform for effective sensing of biomolecules by fluorescence resonance energy transfer (FRET) from quantum dots (QDs) to graphene oxide (GO). The QDs were first modified with a molecular beacon (MB) as a probe to recognize the target analyte. The strong interaction between MB and GO led to the fluorescent quenching of QDs. Upon the recognition of the target, the distance between the QDs and GO increased, and the interaction between target-bound MB and GO became weaker, which significantly hindered the FRET and, thus, increased the fluorescence of QDs. The change in fluorescent intensity produced a novel method for detection of the target. The GO-quenching approach could be used for detection of DNA sequences, with advantages such as less labor for synthesis of the MB-based fluorescent probe, high quenching efficiency and sensitivity, and good specificity. By substituting the MB with aptamer, this strategy could be conveniently extended for detection of other biomolecules, which had been demonstrated by the interaction between aptamer and protein. To the best of our knowledge, this is the first application of the FRET between QDs and GO and opens new opportunities for sensitive detection of biorecognition events.