By examining the DNA structures with various base compositions and contexts at the double-stranded (ds-DNA) and single-stranded (ss-DNA) state, the scientists found that the emission behaviour of the DNA-hosted Cu NPs is particularly dependent on the ss-DNA sequences.

In the study, the team identified that the most efficient host for producing fluorescent Cu NPs is the thymine-rich sequence (see image). Also, echoing previous work, the emission properties of DNA-hosted Cu NPs can be modulated by the sequence length.

The differences in binding nucleophilicity of the DNA heterocyclic nitrogen and exocyclic keto groups to the Cu2+/Cu+ species are believed to be responsible for the sequence-dependent formation of fluorescent Cu NPs.

Full details can be found in the journal Nanotechnology 24 345502

Further reading

Fluorescent gold nanoclusters grown on DNA provide sensing platform (2012)