Molecular spectroscopic characteristics of binding between silk peptide and Reactive Orange K-7R

To investigate the interaction between silk peptide and Reactive Orange K-7R( RK-7R), multiple spectroscopy technologies( ultraviolet visible spectroscopy, fluorescence spectroscopy, synchronous fluorescence spectroscopy and Rayleigh resonance) have been used. The results showed that a non fluorescence complex was formed between the silk peptide and K-7R. The binding distance and binding ratio were calculated as 3. 46 nm and 1∶ 1,respectively. The binding constants increased when ionic liquids including chloride hydroxyethyl trimethyl amine,bromide 1-ethyl-2,3-dimethyl imidazolium, 1-ethyl-2,3-methyl imidazolium bis-[trifluoromethyl-sulfonyl] imide,metal ions( Ca2 +,Pb2 +and Ba2 +),and surfactants CTAB were added into the SP/ K-7R system,while decreased when Cu2 +and Triton X-100 were in the presence. Sodium dodecyl sulfate had no effects on the system.