title: Layer by layer assembled films between hemoglobin and multiwall carbon nanotubes for pH-switchable biosensing.
abstract: Although pH-switchable behaviors have been reported based on multilayer films modified electrodes, their pH-switchable biosensing is still difficult due to the existence of the electroactive mediator. In this study, we report the pH-dependable determination of hydrogen peroxide (H2O2) based on a four-bilayer film fabricated through layer by layer assembly between hemoglobin (Hb) and multiwall carbon nanotubes (MWCNTs). We observed that response of electroactive probe Fe(CN)6(3-) at the multilayer films was very sensitive and reversible to pH values of phosphate buffer solutions phosphate buffer solution with cyclic voltammetry. The reduction peak height of Fe(CN)6(3-) at the multilayer film could reach ∼221μA at pH 3.0 while 0μA at pH 9.0. The linear range for the detection of H2O2 at pH 3.0 was from 12.5μM to 10.4mM, which was much wider than that at pH 9.0. Our results demonstrated that the detection of H2O2 with the proposed modified electrode is dependent on pH values of phosphate buffer solution. Moreover, the component of multilayer films has impacts on the performance of biosensors with pH-switchable behaviors.
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China.
authors.forename: Zhongqin
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China; Affiliated Hospital, Nantong University, Nantong 226021, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Bao
authors.affiliation: Affiliated Hospital, Nantong University, Nantong 226021, China.
authors.forename: Hong
authors.initials: H
authors.lastname: He
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Institute of Analytical Chemistry for Life Science, Nantong University, Nantong 226019, China; School of Public Health, Nantong University, Nantong 226019, China. Electronic address: guhy99@21cn.com.
authors.forename: Haiying
authors.initials: H
authors.lastname: Gu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003208:Concanavalin A / Q000737:chemistry / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D005947:Glucose / Q000378:metabolism; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D006454:Hemoglobins; D037742:Nanotubes, Carbon; D003208:Concanavalin A; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase; D005947:Glucose
keywords: Biosensing; Hemoglobin; Layer by layer assembly; Multiwall carbon nanotubes; pH switchable