Dual-mode ratiometric fluorescent and colorimetric sensor for rapid visual detection of Hg using poly(T)-tailed ssDNA-silver nanoclusters.

Rapid, sensitive, and accurate detection of heavy metal ions is significant for human health and ecological security. Herein, a novel single-stranded DNA with poly(thymidine) tail is tactfully designed as template to synthesize dual-emission silver nanoclusters (ssDNA-AgNCs). The obtained AgNCs simultaneously emit red and green fluorescence, and the red emission can be selectively quenched by Hg, meanwhile the green emission of AgNCs increases synchronously.

Dual-mode ratiometric optical sensor for rapid visual detection of Hg with poly(adenine)-assisted silver nanoclusters anchoring on tetrahedral DNA framework.

Cytosine-rich and poly(adenine)-tailed tetrahedral DNA framework (TDF) is designed as template (A-TDF) for anchoring silver nanoclusters (AgNCs) and igniting the dual-color fluorescence of AgNCs. The resultant DNA-AgNCs simultaneously emits red and green fluorescence, and the quantum yield of red fluorescence is as high as 44.8%.