We studied the excitation energies of zinc porphyrin（ZnP） and zinc porphyrin analogues（ZnP-R） with long-range corrected（LC） density functional theory. We compared three recent LC functionals, wB97XD, CAM-B3LYP, LC-wPBE and functionals B3LYP with the experiments. It was lbund that the low energy excitation is well predicted for ZnP with the LC-wPBE functional based on 6-31G（d） basis set. Excited-state geometry optimiza- tions lbr all the compounds were carried out. It was shown that upon the photo-excitation nearly 1 e transferred to the acceptor unit[dodecafluorosubphthalocyanine, SubPc（F）12] and a highly polarized state formed in compound 5. But after the relaxation of the first excited state, the electron on the acceptor went back to the ZnP a little and then shifted from ZnP to the donor segment[bis（4-hexylphenyl）amino] partially. The computed excited-state radiative lifetime（r） for compound 5 is 943 μs, which shows a reasonable agreement with the experimental observation. According to the long-lived exciton in strong push-pull compound 5, we proposed that electron injection to semiconductor might occur alter vibrational relaxation of excited state.
The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid has been investigated by cyclic voltammetry,linear polarization and chronoamperometry.The graphene nanopowder modified electrode was prepared using the drop coating method,which displayed excellent electrocatalytic activity towards the oxidation of dopamine and uric acid compared with the bare glassy carbon electrode in phosphate buffer solution at pH=7.0.Linear responses for dopamine and uric acid were obtained in the ranges of3.3μmol/L to 249.1μmol/L and 6.7μmol/L to 386.3μmol/L with detection limits of 1.5μmol/L and 2.7μmol/L(S/N=3),respectively.The response time was less than 2 s in case of dopamine and 3 s in case of uric acid,respectively.The results demonstrated that the graphene nanopowder had potential for detecting dopamine and uric acid.
