Stem-directed growth of highly fluorescent silver nanoclusters for versatile logic devices

This work described for the first time the stem-directed growth of silver nanoclusters (AgNCs) with high brightness using the well-chosen hairpin DNA structure. In comparison with the corresponding double-stranded (ds) DNA capped AgNCs, the fluorescence emission of hairpin DNA structure templated AgNCs were lighted up with 12.5-fold enhancement fluorescent intensity by sequence modification with T-loop. It provided a new prospect for precise placement of nanoscale optical elements onto DNA scaffolds. And these DNA protected AgNCs exhibited the base sequence, strand length and microenvironment-dependent fluorescent properties. Benefiting from these properties, versatile logic gates (or, not, inhibit, XNOR, implication) were constructed using different ions as inputs with AgNCs as signal transducer.