Department of Applied Chemistry, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, Republic of Korea.
J Phys Chem B. 2010 Jan 14;114(1):471-9. doi: 10.1021/jp907725f.
We present density functional theory (DFT) and time-dependent DFT (TD-DFT) study of the structures and electronic spectra of small CdSe nanocluster-adenine complexes Cd(n)Se(n)-adenine (n = 3, 6, 10, 13). We examine the changes in the geometries and excitation spectra of the nanoclusters induced by DNA base-binding. By comparing the results calculated for the bare (Cd(n)Se(n)), hydrogen-passivated (Cd(n)Se(n)H(2n)), as well as the corresponding adenine (Ade)-bound clusters (Cd(n)Se(n)-Ade, Cd(n)Se(n)H(2n)-Ade, Cd(n)Se(n)H(2n-2)-Ade), we find that binding with Ade slightly blue-shifts (up to 0.18 eV) the electronic excitations of bare nanoclusters but strongly red-shifts (<1.2 eV) those of hydrogen-passivated nanoclusters. Natural bond orbital analysis shows that the LUMO of Cd(n)Se(n)H(2n)-Ade is a pi* orbital located on the purine ring.
我们提出了密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）对 Cd(n)Se(n)-腺嘌呤（n = 3、6、10、13）小型 CdSe 纳米团簇-腺嘌呤复合物的结构和电子光谱的研究。我们考察了 DNA 碱基结合所引起的纳米团簇几何形状和激发光谱的变化。通过比较裸（Cd(n)Se(n)）、氢钝化（Cd(n)Se(n)H(2n)）以及相应的腺嘌呤（Ade）结合团簇（Cd(n)Se(n)-Ade、Cd(n)Se(n)H(2n)-Ade、Cd(n)Se(n)H(2n-2)-Ade）的计算结果，我们发现与 Ade 结合会略微蓝移（高达 0.18 eV）裸纳米团簇的电子激发，但会强烈红移（<1.2 eV）氢钝化纳米团簇的电子激发。自然键轨道分析表明，Cd(n)Se(n)H(2n)-Ade 的 LUMO 是位于嘌呤环上的 pi*轨道。
