A Dual‐Emissive DNA‐Templated Silver Nanocluster with Near‐Infrared I and II Emission

Abstract

DNA‐stabilized silver nanoclusters (DNA‐Ag_N) are atomically precise and sequence‐tuned nanomaterials with potential applications for deep tissue biomedical imaging. Here, a dual‐emissive DNA‐Ag_N is presented with fluorescence in the first near‐infrared (NIR‐I) spectral window and microsecond‐lived photoluminescence in the second near‐infrared (NIR‐II) spectral window. High‐resolution electrospray ionization mass spectrometry showed that the emitter has the molecular formula (DNA)₂[Ag₁₇]¹¹⁺. The crystallization of (DNA)₂[Ag₁₇]¹¹⁺ was unsuccessful, which prevented the use of X‐ray diffraction to determine its structure. However, sequence variations of the templating DNA oligomer provided insights into nucleobases that are critical for stabilizing the Ag₁₇¹¹⁺. Moreover, addition of an adenosine or thymidine at the 5′‐end of the stabilizing DNA strand maintained the composition and photophysical properties of the (DNA)₂[Ag₁₇]¹¹⁺, suggesting a potential site for conjugation with biomolecules to enable targeted labeling in future bioimaging applications.