Silver Nanoclusters Beacon as Stimuli-Responsive Versatile Platform for Multiplex DNAs Detection and Aptamer-Substrate Complexes Sensing.

An activatable silver nanoclusters beacon (ASNCB) was synthesized through a facile one-pot approach and applied for multiplex DNAs, small molecule, and protein sensing. Multifunctional single-stranded DNA sequences are rationally designed and used for ASNCB in situ synthesis. Via target-responsive structure transformation of ASNCB, target recognition induced ASNCB conformational transition and lit up the fluorescent signal of silver nanoclusters. By further implementing two different color ASNCBs (520 and 600 nm), the parallel multiplexed analysis of two target genes (Influenza A virus genes H1N1 and H5N1) is achieved. Additionally, with the introduction of aptamer for the design of the molecular beacon, the detections of small molecule adenosine triphosphate (ATP) and biomacromolecule thrombin have also been realized. This is the first time that an activatable fluorescent silver nanoclusters (Ag NCs)-based probe and the target recognition have been integrated into a single process, which provides a versatile platform for different analytes in a facile way. The successful application of our proposed ASNCB in real sample analysis and ATP imaging in living cells further displayed its promising potential for fluorescence sensing.