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.
Feng
Jiu-Ju
JJ
The Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Zhu
Jing-Tuo
JT
Xu
Jing-Juan
JJ
Chen
Hong-Yuan
HY
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