DNA‐Dependent Prussian Blue Nanoflowers for Biosensing, Catalysis and Imaging

Abstract While shapes and surface properties of nanomaterials are known to play important roles in defining their properties, it remains challenging to fine‐tune the morphologies systematically and predictably. Considering the extraordinary performance, prussian blue nanoparticles (PBNPs) are selected as the proof‐of‐concept nanomaterials. Herein, a DNA‐dependence approach to fine‐control the morphology of PBNPs via electrostatic interaction‐mediated self‐assembly of inorganic ions and protonated DNA is developed. The regulation of different DNA on the morphology of PBNPs is systematically investigated. 30‐mer Oligo‐C or ‐T (C30/T30) mediates formation of flower‐like PBNPs (PB nanoflowers), whereas cubic structure with different sizes is observed in the presence of 10‐mer oligo‐G or 30‐mer Oligo‐A (G10/A30). Detailed mechanism studies indicate that the protonation of nucleobases is the key factor for the morphological evolution. C30‐dependent PB nanoflowers are superior to PB nanocubes in photothermal properties, peroxidase mimetic activity, photo‐Fenton catalytic performance, and light scattering property, which present 1.2‐, 3.78‐, 1.58‐, 1.93‐fold improvement, respectively. Furthermore, PB nanoflowers mediated by the diblock DNA (sDNA; comprising C30 and complementary strands of the target DNA) unexpectedly acquire biorecognition capabilities. This study opens a new avenue for the systematic and predictable synthesis of PB nanoflowers, which broadens the repertoire of PBNPs for catalysis, biosensing, and imaging.