DNA Assembly of Plasmonic Nanostructures Enables In Vivo SERS-Based MicroRNA Detection and Tumor Photoacoustic Imaging

Controllable self-assembly of the DNA-linked gold nanoparticle(AuNP) architecture for in vivo biomedical applicationsremains a key challenge. Here, we describe the use of the programmedDNA tetrahedral structure to control the assembly of three differenttypes of AuNPs (& SIM;20, 10, and 5 nm) by organizing them intodefined positioning and arrangement. A DNA-assembled "core-satellite"architecture is built by DNA sequencing where satellite AuNPs (10and 5 nm) surround a central core AuNP (20 nm). The density and arrangementof the AuNP satellites around the core AuNP were controlled by tuningthe size and amount of the DNA tetrahedron functionalized on the coreAuNPs, resulting in strong electromagnetic field enhancement derivedfrom hybridized plasmonic coupling effects. By conjugating with theRaman molecule, strong surface-enhanced Raman scattering photoacousticimaging signals could be generated, which were able to image microRNA-21and tumor tissues in vivo. These results providedan efficient strategy to build precision plasmonic superstructuresin plasmonic-based bioanalysis and imaging.