Langmuir
Article
The formation of SO42− was observed in all the photolysis in
the presence of modified NTO (Table 2). Solvated electrons
(e−aq) are also produced in the phototransformation of Phe to
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aq
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the carboxyl group of the inserted amino acid species. The
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by the sulfide radical anion.
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4. CONCLUSIONS
The ratio of the initial rates of photolysis at 254 nm of
phenylalanine (Phe), decreases in the presence of carbon
nanotubes. The mass of nanotubes produces an exponential
attenuation of the photolytic decomposition. The photolytic
decay of Phe in air-saturated solution takes place with
formation of tyrosine (Tyr), that is inhibited in the presence
of NTO.
Total carbon analyses (TCA), 13C-SSNMR, and XPS spectra
showed the photofunctionalization of NTO, modified by SO2,
by insertion of Phe onto the nonoxidized episulfide
intermediate. The insertion on the matrix may occur along
with the extrusion of a sulfide radical anion (•S−) which
2−
undergo subsequent oxidation to SO4
.
AUTHOR INFORMATION
Corresponding Author
■
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We thank the Brazilian Government Agency Coordenaca
̧
o de
̃
́
Aperfeico
̧
amento de Pessoal de Nivel Superior (CAPES), Projeto
CAPES/DGU 219/2010, and the Spanish Ministerio de
Educacion, Cultura y Deporte, DGU, Project PHB2009-0057-
́
PC, for financial support.
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