Homo-FRET mediated antenna effect on the DNA tetrahedron for hepatitis C virus DNA detection

Home-Förster resonance energy transfer (Homo-FRET) has been widely utilized in artificial light-harvesting systems to construct antenna structures with enhanced energy-capture efficiency. Although these systems typically exhibit remarkable antenna effects and signal amplification capabilities, their application in detection systems remains limited. Herein, we reported a rationally designed homo-FRET mediated three-donor/one-acceptor (3D-A) antenna nanostructure assembled on a rigid DNA tetrahedron scaffold for the quantitative detection of Hepatitis C virus (HCV) DNA. Robust homo-FRET interactions among the three donors significantly amplified the hetero-FRET efficiency to the single acceptor, generating an enhanced antenna effect. Upon target recognition, the system provided a ratiometric readout, where the fluorescence intensity ratio between Cy5 and Cy3 increased proportionally with HCV DNA concentration. The proposed 3D-A nanoprobe exhibited a linear response range from 1 to 100 nM with a detection limit of 65 pM. Furthermore, by simply altering the target-binding sequence, this system offered a high versatile platform for universal DNA detection detection.