Electrochemical biosensor for the detection of H2O2 from living cancer cells based on ZnO nanosheets.
In this work, direct electron transfer of cytochrome c (cyt. c)--a model for studying the electron transfer of enzymes is achieved at hexagonal ZnO nanosheets by one-step electrodeposition. UV-vis spectra and electrochemical data demonstrate that such ZnO nanosheets can supply a bio-compatible surface to keep the bioactivity of cyt. c. The redox formal potential (E(0)') of cyt. c is estimated to be 338.2+/-4.3 mV (vs. AgAgCl) at the nanostructured ZnO surface. This value is much more positive than those of enzymes previously obtained at other metal oxides and zeolite surfaces. Experiment data show, under the optimized potential of 0.0 V (vs. AgAgCl), the electrochemical determination of H(2)O(2) is free from not only anodic interferences like ascorbic acid (AA) and dopamine (DA), but also a cathodic interference-O(2). Such an excellent selectivity enable the present H(2)O(2) biosensor determine the extracellular H(2)O(2) released from living human hepatoma cells.
Rui
Qi
Q
Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China.
Komori
Kikuo
K
Tian
Yang
Y
Liu
Haiqing
H
Luo
Yongping
Y
Sakai
Yasuyuki
Y
D000327:Adsorption; D000818:Animals; D055162:Biocatalysis; D015374:Biosensing Techniques; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism*; D004563:Electrochemistry; D004579:Electron Transport; D006736:Horses; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D043942:Nanotubes / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry*
D045304:Cytochromes c; D006861:Hydrogen Peroxide; D015034:Zinc Oxide