Enhanced biosensing performance of mesoporous SnO2 multilayer film in interfacing hemoglobin.
Through alternative adsorption of dextran sulfate (DS) and mesoporous SnO2 (Meso-SnO2), {Meso-SnO2/DS}n films were constructed and applied for the immobilization of hemoglobin (Hb). For comparison, the same-sized non-mesoporous SnO2 nanopraticles (Nonmeso-SnO2) based films were also prepared. Thus-formed films were characterized by many techniques in detail. The electrochemical impedance spectroscopy (EIS, using ferricyanide/ferrocyanide as a redox probe) experiments confirmed the charge transfer resistance increased linearly with the number of Meso-SnO2/DS bilayers, which was smaller than that of Nonmeso-SnO2/DS bilayers. Further EIS, UV-vis and AFM experiments indicate that Meso-SnO2/DS film exhibit enhanced immobilization ability of Hb with favorable orientation in comparison with that of Nonmeso-SnO2/DS film. The adsorbed Hb at Meso-SnO2/DS film showed a good direct electron transfer behavior with the heterogeneous electron transfer rate constant (ks) of 8.89 +/-0.32 s(-1), and excellent electrocatalysis to the reduction of O2 and H2O2 in pH 7.0 buffers.
The Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Jiu-Ju
JJ
Feng
Jing-Tuo
JT
Zhu
Jing-Juan
JJ
Xu
Hong-Yuan
HY
Chen
D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004563:Electrochemistry; D006454:Hemoglobins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017971:Tin Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D006454:Hemoglobins; D055767:Immobilized Proteins; D017971:Tin Compounds; C045358:stannic oxide