• 文献标题:   Spectroscopic characterization of tetracationic porphyrins and their noncovalent functionalization with graphene
  • 文献类型:   Article
  • 作  者:   YE TX, YE SL, CHEN DM, CHEN QA, QIU B, CHEN X
  • 作者关键词:   cationic porphyrin, graphene, noncovalent functionalization
  • 出版物名称:   SPECTROCHIMICA ACTA PART AMOLECULAR BIOMOLECULAR SPECTROSCOPY
  • ISSN:   1386-1425
  • 通讯作者地址:   Fuzhou Univ
  • 被引频次:   28
  • DOI:   10.1016/j.saa.2011.10.070
  • 出版年:   2012

▎ 摘  要

In this study, the noncovalent functionalization of graphene with cationic porphyrins in an aqueous medium was investigated using UV-vis and fluorescence approaches. To characterize the interaction between graphene and cationic porphyrins, 5,10,15,20-tetra (4-pyridyl)-21H,23H-porphine, 5,10,15,20-tetrakis (1-methyl-4-pyridinio) porphyrin tetra (p-toluenesulfonate) and 5,10,15,20-tetrakis (4-trimethylammoniophenyl) porphyrin tetra (p-toluenesulfonate) porphyrin were chosen as reagents. The intermolecular interactions were found to occur immediately after mixing the cationic porphyrins with graphene. The absorption spectra of the cationic porphyrins after mixing with graphene showed distinct red shifts of the Soret and Q-bands compared to free cationic porphyrins indicating that interactions occur between the cationic porphyrins and graphene. A strong fluorescence quenching of the cationic porphyrins in the presence of graphene indicated that efficient electron or energy transfer occurred from the excited state of the cationic porphyrins to graphene. Cationic porphyrins were immobilized on the surface of graphene through electrostatic and pi-pi stacking interactions, and the chemical shape of graphene played an important role in the intermolecular interactions and the red shift extent of cationic porphyrins is mostly dependent on the functional groups and charges of the graphene surface. The results show that less functional groups on the graphene's surface and edge would lead to stronger pi-pi stacking interactions between graphene and cationic porphyrins. (C) 2011 Elsevier B.V. All rights reserved.