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Effect of Silver Nanoparticles on the Electron Transfer Reactivity and the Catalytic Activity of Myoglobin
Author(s) -
Gan Xin,
Liu Tao,
Zhong Jun,
Liu Xinjian,
Li Genxi
Publication year - 2004
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200400080
Subject(s) - myoglobin , silver nanoparticle , electron transfer , catalysis , reactivity (psychology) , chemistry , redox , nanoparticle , pyrolytic carbon , photochemistry , hydrogen peroxide , biosensor , surface plasmon resonance , inorganic chemistry , materials science , nanotechnology , organic chemistry , medicine , biochemistry , alternative medicine , pathology , pyrolysis
Silver nanoparticles (11±1.5 nm) could greatly enhance the electron‐transfer reactivity of myoglobin (Mb) and its catalytic ability toward hydrogen peroxide (H 2 O 2 ). Direct fast electron transfer between Mb and a pyrolytic graphite (PG) electrode was achieved, and a pair of well‐defined, quasireversible redox peaks was obtained. The cathodic and anodic peaks were located at −329 and −281 mV, respectively. Meanwhile, the catalytic ability of the protein toward the reduction of H 2 O 2 was also studied, and a H 2 O 2 biosensor was subsequently fabricated. Its detection limit was 1.0×10 −6 M with a sensitivity of 0.0205 μ A per μ M of H 2 O 2 . The apparent Michaelis–Menten constant was calculated to be 1303 μ M . Flocculation assay showed that the protein maintained plasmon layers surrounding the surface of silver nanoparticles and avoided silver‐nanoparticle aggregation. On the other hand, UV‐visible spectroscopy studies revealed that silver nanoparticles could induce a small change of the heme‐group environment of the protein; this contributed to the enhancement of the electron‐transfer reactivity and the catalytic activity.