DNA Framework‐Templated Fabrication of Ultrathin Electroactive Gold Nanosheets

Generally, two‐dimensional gold nanomaterials have unique properties and functions that offer exciting application prospects. However, the crystal phases of these materials tend to be limited to the thermodynamically stable crystal structure. Herein, we report a DNA framework‐templated approach for the ambient aqueous synthesis of freestanding and microscale amorphous gold nanosheets with ultrathin sub‐nanometer thickness. We observe that extended single‐stranded DNA on DNA nanosheets can induce site‐specific metallization and enable precise modification of the metalized nanostructures at predefined positions. More importantly, the as‐prepared gold nanosheets can serve as an electrocatalyst for glucose oxidase‐catalyzed aerobic oxidation, exhibiting enhanced electrocatalytic activity (~3‐fold) relative to discrete gold nanoclusters owing to a larger electrochemical active area and wider band gap. The proposed DNA framework‐templated metallization strategy is expected to be applicable in a broad range of fields, from catalysis to new energy materials. Microscale (width of ~20 μm) and ultrathin (0.49 nm) amorphous Au nanosheets are synthesized at room temperature in an aqueous solution using DNA nanosheets with extended single‐stranded DNA (ssDNA) with a larger spacing (16.7 nm) for the first time. The extended ssDNA induces metallization and enables further precise modification of the metalized nanostructures at predefined positions.