Designing Atomically Precise Gold Nanocluster Architectures with DNA-Guided Self-Assembly and Biofunctionalization Approaches

Atomically precise gold nanoclusters (AuNCs) are nanomolecular species with unique optoelectronic properties, both at the individual and assembled levels. Here, we demonstrate the precise ligand engineer-ing of AuNCs, enabling the controlled grafting of single-stranded oligonucleotides onto atomically defined AuNCs of different sizes (Au₁₈ and Au₂₅), which emit in the NIR-I (600–800 nm) and NIR-II (900–1300 nm) spectral windows, respectively. These biofunctionalized AuNCs, which can be considered nanomo-lecular building blocks, were thoroughly characterized using complementary analytical and optical tech-niques, including absorption and fluorescence spectroscopy, mass spectrometry, liquid chromatography, and gel electrophoresis. Through selective DNA hybridization, we successfully assembled AuNC dimers, trimers, and AuNC-dye nanosystems with high reproducibility and yield. This work lays the foundation for the design of AuNC-DNA superstructures with potential applications in optoelectronics, sensing, and nanomedicine.