Smart flared-nanokites with ultra-high fluorescence enhancement for multiplexing virus DNA biosensing

A label-free sensing paradigm based on smart flared-nanokites is developed for multiplexed detection of virus DNA. A nanokite consists of silver nanoclusters beacons (Ag NCBs) immobilized on gold nanoparticle (Au NP) core. Ag NCB, possessing hairpin-shaped configuration, includes three functional domains: silver nanoclusters (Ag NCs) as the reporter, conjugated loop as recognizing element, and stem attached thiol. Via thiol-gold bond, Ag NCBs self-assemble on Au NP and form Ag NCBs/Au NP. In this conformation, close proximity of Ag NCs to Au NP leads to quenching fluorescence owing to energy transfer. However, upon recognizing loop binds to target, concomitant flying of Ag NCs from Au NP can be monitored as corresponding fluorescence enhancement, termed a flared-nanokite. Interestingly, ultra-high fluorescence recovery rate is calculated as 4379.2% (1300.4%) for G-/ R-nanokite. Moreover, through by bicolor Ag NCBs simultaneously immobilize on Au NP, multicolor flared-nanokite for multichannel detecting DNAs has been successfully constructed based on multistimuli-responsive effect, demonstrating its promising application in accurate diagnosis and treatment.

Automated summary

A label-free sensing method for multiplexed detection of virus DNA is developed using smart flared-nanokites. The flared-nanokites consist of silver nanoclusters beacons immobilized on gold nanoparticles. The close proximity of silver nanoclusters to gold nanoparticles leads to quenching of fluorescence, but upon target binding, the release of silver nanoclusters results in fluorescence enhancement. Multicolor flared-nanokites for multichannel DNA detection have been successfully constructed, demonstrating their promising application in accurate diagnosis and treatment.