title: Amperometric glucose biosensor based on glucose oxidase dispersed in multiwalled carbon nanotubes/graphene oxide hybrid biocomposite.
abstract: An amperometric glucose biosensor based on enhanced and fast direct electron transfer (DET) of glucose oxidase (GOx) at enzyme dispersed multiwalled carbon nanotubes/graphene oxide (MWCNT/GO) hybrid biocomposite was developed. The fabricated hybrid biocomposite was characterized by transmission electron microscopy (TEM), Raman and infrared spectroscopy (IR). The TEM image of hybrid biocomposite reveals that a thin layer of GOx was covered on the surface of MWCNT/GO hybrid composite. IR results validate that the hybrid biocomposite was formed through the electrostatic interactions between GOx and MWCNT/GO hybrid composite. Further, MWCNT/GO hybrid composite has also been characterized by TEM and UV-visible spectroscopy. A pair of well-defined redox peak was observed for GOx immobilized at the hybrid biocomposite electrode than that immobilized at the MWCNT modified electrode. The electron transfer rate constant (Ks) of GOx at the hybrid biocomposite was calculated to be 11.22s(-1). The higher Ks value revealed that fast DET of GOx occurred at the electrode surface. Moreover, fabricated biosensor showed a good sensitivity towards glucose oxidation over a linear range 0.05-23.2mM. The limit of detection (LOD) was estimated to be 28μM. The good features of the proposed biosensor could be used for the accurate detection of glucose in the biological samples.
authors.affiliation: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
authors.forename: Selvakumar
authors.initials: S
authors.lastname: Palanisamy
authors.forename: Srikanth
authors.initials: S
authors.lastname: Cheemalapati
authors.forename: Shen-Ming
authors.initials: SM
authors.lastname: Chen
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D005898:Glass / Q000737:chemistry; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000378:metabolism*; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D037742:Nanotubes, Carbon; D010087:Oxides; D006108:Graphite; D005949:Glucose Oxidase; D005947:Glucose
keywords: Direct electron transfer; Electrocatalysis; Glucose oxidase; Glucose sensor; Hybrid biocomposite; MWCNT/GO