title: Direct electron transfer of glucose oxidase and biosensing for glucose based on PDDA-capped gold nanoparticle modified graphene/multi-walled carbon nanotubes electrode.
abstract: In this work, poly (diallyldimethylammonium chloride) (PDDA)-capped gold nanoparticles (AuNPs) functionalized graphene (G)/multi-walled carbon nanotubes (MWCNTs) nanocomposites were fabricated. Based on the electrostatic attraction, the G/MWCNTs hybrid material can be decorated with AuNPs uniformly and densely. The new hierarchical nanostructure can provide a larger surface area and a more favorable microenvironment for electron transfer. The AuNPs/G/MWCNTs nanocomposite was used as a novel immobilization platform for glucose oxidase (GOD). Direct electron transfer (DET) was achieved between GOD and the electrode. Field emission scanning electron microscopy (FESEM), UV-vis spectroscopy and cyclic voltammetry (CV) were used to characterize the electrochemical biosensor. The glucose biosensor fabricated based on GOD electrode modified with AuNPs/G/MWCNTs demonstrated satisfactory analytical performance with high sensitivity (29.72mAM(-1)cm(-2)) and low limit of detection (4.8 µM). The heterogeneous electron transfer rate constant (ΚS) and the apparent Michaelis-Menten constant (Km) of GOD were calculated to be 11.18s(-1) and 2.09 mM, respectively. With satisfactory selectivity, reproducibility, and stability, the nanostructure we proposed offered an alternative for electrode fabricating and glucose biosensing.
authors.affiliation: School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Yu
authors.forename: Zuanguang
authors.initials: Z
authors.lastname: Chen
authors.forename: Sijing
authors.initials: S
authors.lastname: He
authors.forename: Beibei
authors.initials: B
authors.lastname: Zhang
authors.forename: Xinchun
authors.initials: X
authors.lastname: Li
authors.forename: Meicun
authors.initials: M
authors.lastname: Yao
mesh_terms: D000498:Allyl Compounds / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D004566:Electrodes; D004579:Electron Transport; D005947:Glucose / Q000302:isolation & purification*; D005949:Glucose Oxidase / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry
chemical_list: D000498:Allyl Compounds; D037742:Nanotubes, Carbon; D000644:Quaternary Ammonium Compounds; D006046:Gold; D006108:Graphite; C508190:diallyldimethylammonium chloride; D005949:Glucose Oxidase; D005947:Glucose
keywords: Biosensor; Direct electron transfer; Glucose oxidase; Gold nanoparticle; Graphene; Multi-walled carbon nanotube