A Comparison of a Nanostructured Enzymeless Au/Fe2O3/MWCNTs/GCE Electrode and a GOx Modified One in Electrocatalytic Detection of Glucose. Issue 9 (24th May 2018)

• Record Type: Journal Article
• Authors: Mohammadi, Fatemeh; Vesali‐Naseh, Masoud; Khodadadi, Abbas Ali; Mortazavi, Yadollah
• Is Part Of: Electroanalysis. Volume 30:Issue 9(2018)
• Page Start: 2044
• Page End: 2052
• Publication Date: 2018-05-24
• Subjects: Carbon nanotubes -- Iron oxide -- Gold -- Glucose biosensors; Electrochemical analysis -- Periodicals; Chemistry, Analytical -- Periodicals; Electrochemistry -- Periodicals; 543.4
• DOI: 10.1002/elan.201800164
• Languages: English
• ISSNs: 1040-0397

Abstract

Abstract: Acid functionalized multi‐walled carbon nanotubes (f‐MWCNTs) were decorated with Au and Fe2 O3 nanoparticles (FeONPs) and deposited on glassy carbon electrode (GCE). The resulting hybrid Au/Fe2 O3 /f‐MWCNTs/GCE electrode and the one further modified by glucose oxidase were compared for detection of glucose. FeONPs and Au were deposited on the f‐MWCNTs by sonication‐assisted precipitation and deposition‐precipitation methods, respectively. The morphology and structure of the samples were characterized by transmission electron microscopy, scanning electron microscopy, X‐ray diffraction and Raman spectroscopy. A uniform distribution of FeONPs with an average size of 5 nm increased the surface area of functionalized nanotubes from 39 to 50 m 2 /g. The electrocatalytic glucose detection on the modified electrodes was evaluated using cyclic voltammetry and chronoamperometry in 0.1 M phosphate buffer solution at pH 7.0. The non‐enzymatic and enzymatic electrodes show sensitivity of 512.4 and 921.4 mA/mM.cm 2 and detection limit of 1.7 and 0.9 mM, respectively. The enzymatic and enzymeless electrodes retained more than 70 % and 80 % of their cathodic faradic current after 70 days, respectively. The sensing mechanism of the non‐enzymatic biosensor is described through the reaction of glucose with iron (III) ions, while in the case of enzymatic electrode, glucose is oxidized by glucose oxidase. Abstract :