Time-Resolved Vibrational Fingerprints for Two Silver Cluster-DNA Fluorophores
Time-Resolved Vibrational Fingerprints for Two Silver Cluster-DNA Fluorophores
复制标题
DOI：
10.1021/acs.jpclett.0c02486
复制
发表时间：
2020-11-05
影响因子：
5.7
通讯作者：
Kohler, Bern
中科院分区：
文献类型：
--
作者：
Zhang, Yuyuan;He, Chen;Kohler, Bern
以DNA为模板的银团簇是生色团，其中的核碱基编码了团簇的光谱和亮度。我们描述了两个几乎相同的Ag-10(6+)簇的配位环境，这两个簇由18个核苷酸链CCCCA、CCCCT、CCCX、TTTT组成，X=鸟苷和肌苷。首次利用可见激发和中红外探测的飞秒时间分辨红外光谱(TRIR)研究了金属团簇的电子激发对核基振动模式的响应。在1400-1720 cm(-1)范围内的丰富的瞬时TRIR峰与可见光发射同步衰减。观察到与单个鸟苷/肌苷以及胞苷的子集相关的特定红外特征，但没有观察到胸苷。这些指纹表明，银团簇加合物与其多齿DNA配体之间的键网络可以被破译，从而合理地调节分子银发色团的配位，从而调节分子发色团的光谱。
DNA-templated silver clusters are chromophores in which the nucleobases encode the cluster spectra and brightness. We describe the coordination environments of two nearly identical Ag-10(6+) clusters that form with 18-nucleotide strands CCCCA CCCCT CCCX TTTT, with X = guanosine and inosine. For the first time, femtosecond time-resolved infrared (TRIR) spectroscopy with visible excitation and mid-infrared probing is used to correlate the response of nucleobase vibrational modes to electronic excitation of the metal cluster. A rich pattern of transient TRIR peaks in the 1400-1720 cm(-1) range decays synchronously with the visible emission. Specific infrared signatures associated with the single guanosine/inosine along with a subset of cytidines, but not the thymidines, are observed. These fingerprints suggest that the network of bonds between a silver cluster adduct and its polydentate DNA ligands can be deciphered to rationally tune the coordination and thus spectra of molecular silver chromophores.