DNA secondary structures, such as dimers and hairpins, are important for the synthesis of DNA template-embedded silver nanoclusters (DNA/AgNCs). However, the arrangement of AgNCs within a given DNA template and how the AgNC influences the secondary structure of the DNA template are still unclear. Here, we introduce a noncanonical head-to-head hairpin DNA nanostructure that is driven by orange-emissive AgNCs. Through detailed in-gel analysis, sugar backbone switching, inductively coupled plasma mass spectrometry, small-angle X-ray scattering, and small angle neutron scattering, we show that the orange-emissive AgNCs mediate cytosine-Ag-cytosine bridging between two six-cytosine loop (6C-loop) hairpin DNA templates. Unlike green, red, or far-red emissive AgNCs, which are embedded inside a hairpin and duplex DNA template, the orange-emissive AgNCs are localized on the interface between the two 6C-loop hairpin DNA templates, thereby linking them. Moreover, we found that deoxyribose in the backbone of the 6C-loop at the third and fourth cytosines is crucial for the formation of the orange-emissive AgNCs and the head-to-head hairpin DNA structure. Taken together, we suggest that the specific wavelength of AgNCs fluorescence is determined by the mutual interaction between the secondary or tertiary structures of DNA- and AgNC-mediated intermolecular DNA cross-linking.
Bibliographical noteFunding Information:
This work was supported by the Korea Research Fellowship Program funded by the Ministry of Science and ICT (NRF-2017H1D3A1A01014182, NRF-2017M2A2A6A04093177), the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (Grant No. HI16C1118), by a grant from the Basic Science Research Program through the National Research Foundation (NRF) (Grant No. 2018R1A6A1A03025607, NRF-2018R1D1A1B07051125) funded by the Ministry of Education, Republic of Korea, by Brain Korea 21 (BK21) PLUS program, by the Yonsei University Research Fund of 2017-22-0046 and Novo-Nordisk Foundation Grant No. NNF16OC0021832.
© 2020 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)