Human sulfite oxidase electrochemistry on gold nanoparticles modified electrode.
The present study reports a facile approach for sulfite biosensing, based on enhanced direct electron transfer of a human sulfite oxidase (hSO) immobilized on a gold nanoparticles modified electrode. The spherical core shell AuNPs were prepared via a new method by reduction of HAuCl(4) with branched poly(ethyleneimine) in an ionic liquids resulting particles with a diameter less than 10nm. These nanoparticles were covalently attached to a mercaptoundecanoic acid modified Au-electrode where then hSO was adsorbed and an enhanced interfacial electron transfer and electrocatalysis was achieved. UV/Vis and resonance Raman spectroscopy, in combination with direct protein voltammetry, are employed for the characterization of the system and reveal no perturbation of the structural integrity of the redox protein. The proposed biosensor exhibited a quick steady-state current response, within 2 s, a linear detection range between 0.5 and 5.4 μM with a high sensitivity (1.85 nA μM(-1)). The investigated system provides remarkable advantages in the possibility to work at low applied potential and at very high ionic strength. Therefore these properties could make the proposed system useful in the development of bioelectronic devices and its application in real samples.
Institut für Biochemie und Biologie, Universität Potsdam, Golm, Germany.
Stefano
S
Frasca
Oscar
O
Rojas
Johannes
J
Salewski
Bettina
B
Neumann
Konstanze
K
Stiba
Inez M
IM
Weidinger
Brigitte
B
Tiersch
Silke
S
Leimkühler
Joachim
J
Koetz
Ulla
U
Wollenberger
D002384:Catalysis; D002712:Chlorides / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D004579:Electron Transport; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D017612:Gold Compounds / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry*; D010316:Particle Size; D011094:Polyethyleneimine / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013447:Sulfites / Q000032:analysis*
D002712:Chlorides; D004800:Enzymes, Immobilized; D017612:Gold Compounds; D052578:Ionic Liquids; D013447:Sulfites; D006046:Gold; C024568:gold tetrachloride, acid; D011094:Polyethyleneimine; D006861:Hydrogen Peroxide; D050862:Oxidoreductases Acting on Sulfur Group Donors; C503599:SUOX protein, human