Target-induced quenching for highly sensitive detection of nucleic acids based on label-free luminescent supersandwich DNA/silver nanoclusters.

Luminescent silver nanoclusters (AgNCs) were anchored by designed oligonucleotides, acting as fluorescent labels. They hybridized with specific nucleic acid targets to form a supersandwich structure resulting in the fluorescence intensity of the DNA/AgNCs decreasing linearly with respect to the concentration of the target DNA.