Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu, 804-8550, Japan.
Photochem Photobiol Sci. 2012 Feb;11(2):289-93. doi: 10.1039/c1pp05250k. Epub 2011 Nov 22.
Porphyrins linking amphiphilic peptides were applied as photosensitisers, assuming that they would interact with the H(+) reduction catalyst, polymer-protected colloidal Pt or Ir. The close orientation of the porphyrin and metal catalyst may facilitate efficient electron transfer. The porphyrin linking a peptide containing glutamic acids (Glu), Ac-Cys(porph)-Glu-Val-Glu-Val-NH(2) (2), was an effective sensitiser for the H(2) generation reaction in the presence of N-benzyldihydronicotinamide and colloidal Pt or Ir in aqueous media under visible light illumination. At pH 5 and 7, 2 was a more efficient photosensitiser than tetrakis(p-carboxyphenyl)porphyrin (TCPP). The efficiency of H(+) reduction catalysts was in the order Ir-pGlu (polyglutamic acid) > Ir-PVP (polyvinylpyrrolidone) > Pt-PVP. Dynamic light scattering and scanning electron microscopy measurements showed that large particles formed when colloidal metal solutions were produced by microwave irradiation. Fluorescence quenching experiments suggested that electron transfer occurred from the photoexcited porphyrin to the colloidal Ir.
卟啉连接两亲肽被用作光敏剂，假设它们将与 H(+)还原催化剂、聚合物保护胶体 Pt 或 Ir 相互作用。卟啉和金属催化剂的紧密取向可能有利于有效的电子转移。含有谷氨酸 (Glu) 的肽连接的卟啉，Ac-Cys(porph)-Glu-Val-Glu-Val-NH(2) (2)，在可见光照射下，在 N-苄基二氢烟酰胺和胶体 Pt 或 Ir 的存在下，在水相介质中是 H(2)生成反应的有效敏化剂。在 pH 5 和 7 下，2 比四(对羧基苯基)卟啉 (TCPP) 更有效。H(+)还原催化剂的效率顺序为 Ir-pGlu（聚谷氨酸）>Ir-PVP（聚乙烯吡咯烷酮）>Pt-PVP。动态光散射和扫描电子显微镜测量表明，当通过微波照射产生胶体金属溶液时，会形成大颗粒。荧光猝灭实验表明，电子从光激发的卟啉转移到胶体 Ir 上。
