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Single-walled carbon nanotubes (SWCNTs) because of its ideal one-dimensional structure exhibits many peculiar physical and chemical characteristics, are widely used in biomedical fields, such as bio-electrochemical sensors, drug delivery carriers, tissue engineering materials and so on. However, in biomedical applications, are involved in bio-nano interactions. In this paper vivo aromatic clusters of two essential amino acids - phenylalanine (Phe) and tryptophan (Trp) adsorbed on SWCNTs, using near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and synchrotron radiation photoemission spectroscopy ( SRPES) technology research SWCNTs and Phe, Trp interaction mechanism between. Meanwhile, the use of different concentrations of HNO3, concentrated HNO3 / acid mixture of concentrated H2SO4 were carboxylated SWCNTs, Raman spectroscopy (Raman spectroscopy) to study the carboxylation under different conditions, putting forward the best conditions for carboxylation. Major research work and results are: 1 SWCNTs adsorption mechanism of Trp was SWCNTs method using vacuum filtration membrane, the membrane was incubated in a saturated SWCNTs Trp solution for 1 hour to obtain the adsorption of Trp SWCNTs films were tested SWCNTs, adsorption Trp The SWCNTs, Trp the CK edge, OK edge, NK edge NEXAFS spectra and C1s, O1s, N1s SPPES spectrum. A) after adsorption, Trp sample CK edge NEXAFS spectrum 288.2eV absorption peak moves towards lower energy 0.6eV, SRSPE carboxyl C1s spectrum binding energy to low-energy mobile 0.5eV, shows clearly involved carboxyl interface interactions. 2) after adsorption, NK edge NEXAFS spectrum and N1s SRPES peak shape and energy position changes can be ignored no involvement implies the amino interfacial interactions. 3) after adsorption, OK edge NEXAFS spectrum peak shape change and combine O1s SRPES spectra showed that only the carboxyl group in the molecule Trp C = O O atom in the interfacial interactions. 2 SWCNTs Phe adsorption mechanism of SWCNTs obtained by vacuum filtration method membrane, the membrane was incubated in a saturated SWCNTs Phe in the solution for 1 hour to obtain the adsorption of Phe SWCNTs films were tested SWCNTs, the adsorption of Phe SWCNTs, Phe of CK edge, OK edge, NK edge NEXAFS spectra and C1s, O1s, N1s SPPES spectrum. A) after adsorption, Phe sample of CK NEXAFS spectrum 288.1eV absorption peak shifted to lower energy by about 0.5eV, instructions exist between Phe and SWCNTs interfacial interaction. 2) after adsorption, OK forward side edge NEXAFS spectra revealed significant changes in the carboxyl group C = O of the O-atom interaction was involved in the interface, O1s SRPES spectrum only carbonyl further proof of the O atoms of the interfacial interaction . 3) after adsorption, NK edge NEXAFS peak intensity change that the N atom of the amino group is also involved in the interaction of the interface. 4) after adsorption, C1s SRPES same spectral changes proved carboxyl O atoms and amino N atoms are involved in the interfacial interactions. 3 SWCNTs carboxylation Conditions SWCNTs by Raman spectra in different conditions carboxylation carboxylation of research. Raman spectra of radial breathing mode (RBM) peak changes show that the majority of the 15M HNO3 SWCNTs wall destroyed, the optimal oxidation conditions should be about 10M HNO3. Raman spectra peaks D and G peak intensity further illustrates about 10M HNO3 is the best oxidizing conditions.
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