Positive dendritic effect in DNA/porphyrin composite photocurrent generators containing dendrimers as the stationary phase
Positive dendritic effect in DNA/porphyrin composite photocurrent generators containing dendrimers as the stationary phase
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DOI：
10.1021/cm061812i
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发表时间：
2006-12-12
影响因子：
8.6
通讯作者：
Kikuchi, Jun-ichi
中科院分区：
文献类型：
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作者：
Ogasawara, Shin;Ikeda, Atsushi;Kikuchi, Jun-ichi
在本研究中，我们使用PAMAM树枝状大分子（G1-G4）作为固定相，将存款卟啉插层DNA沉积到ITO电极上。树状聚合物的外部氨基部分的表面密度，即，表面的阳离子电荷密度随着每一代的增加而增加，并且相应地通过静电相互作用和嵌入增加了DNA和卟啉（1）单元的表面覆盖度。所得的树枝状聚合物-DNA-1膜足够稳定，它们不会从ITO电极上剥离。所得电极响应于可见光照射而产生光电流波。光电流在增加树枝状聚合物的生成时呈指数增加，即，我们在这些系统中观察到了正的树突效应; 2实际上，G4-DNA-1膜的光电流（在440 nm处为77.5 nA cm（-2））约为100 nm。G1-DNA-1膜的量子产率（1.0%）是G1-DNA-1膜的量子产率（0.2%）的5倍。此外，二维聚合物G4作为固定相的性能远优于一维聚合物聚烯丙基胺盐酸盐（PAH）的性能，为上级。
In this study, we used PAMAM dendrimers (G1-G4) as stationary phases to deposit porphyrin-intercalated DNA onto ITO electrodes. The surface density of the external amino moieties of the dendrimers, i.e., the cationic charge density on the surface, increased with each generation, and correspondingly increased the surface coverage of DNA and porphyrin (1) units through electrostatic interactions and intercalation. The resulting dendrimer-DNA-1 membranes were sufficiently stable that they did not peel off the ITO electrodes. The resulting electrodes generated photocurrent waves in response to irradiation with visible light. The photocurrent increased exponentially upon increasing the generation of the dendrimer, i.e., we observed a positive dendritic effect in these systems; actually, the photocurrent for the G4-DNA-1 membrane (77.5 nA cm(-2) at 440 nm) was ca. nine times larger than that for the G1-DNA-1 membrane (8.5 nA cm(-2) at 440 nm), and the quantum yield for the former (1.0%) was five times larger than that for the latter (0.2%). Furthermore, the performance of the two-dimensional polymer G4 as a stationary phase was far superior to that of the one-dimensional polymer poly( allylamine hydrochloride) (PAH).