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Avidin and Glucose Oxidase‐non‐covalently Functionalized Multi‐walled Carbon Nanotubes: A New Analytical Tool for Building a Bienzymatic Glucose Biosensor
Author(s) -
Gallay Pablo A.,
Rubianes María D.,
Gutierrez Fabiana A.,
Rivas Gustavo A.
Publication year - 2019
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201900202
Subject(s) - glucose oxidase , avidin , biosensor , amperometry , carbon nanotube , chemistry , glassy carbon , surface modification , hydroquinone , horseradish peroxidase , covalent bond , nuclear chemistry , chromatography , electrode , materials science , nanotechnology , cyclic voltammetry , organic chemistry , biotinylation , electrochemistry , biochemistry , enzyme
We report an innovative supramolecular architecture for bienzymatic glucose biosensing based on the non‐covalently functionalization of multi‐walled carbon nanotubes (MWCNTs) with two proteins, glucose oxidase (GOx) (to recognize glucose) and avidin (to allow the specific anchoring of biotinylated horseradish peroxidase (b‐HRP)). The optimum functionalization was obtained by sonicating for 10 min 0.50 mg mL −1 MWCNTs in a solution of 2.00 mg mL −1 GOx+1.00 mg mL −1 avidin prepared in 50 : 50 v/v ethanol/water. The sensitivity to glucose for glassy carbon electrodes (GCE) modified with MWCNTs‐GOx‐avidin dispersion and b‐HRP (GCE/MWCNTs‐GOx‐avidin/b‐HRP), obtained from amperometric experiments performed at −0.100 V in the presence of 5.0×10 −4 M hydroquinone, was (4.8±0.3) μA mM −1 (r 2 =0.9986) and the detection limit was 1.2 μM. The reproducibility for 5 electrodes using the same MWCNTs/GOx‐avidin dispersion was 4.0 %, while the reproducibility for 3 different dispersions and 9 electrodes was 6.0 %. The GCE/MWCNT‐GOx‐avidin/b‐HRP was successfully used for the quantification of glucose in a pharmaceutical product and milk.