Hydrogen peroxide detection at a horseradish peroxidase biosensor with a Au nanoparticle-dotted titanate nanotube|hydrophobic ionic liquid scaffold.
In this work, a novel sensing scaffold, consisting Au nanoparticle (GNP)-dotted TiO(2) nanotubes (TNTs) as the rigid material and the hydrophobic ionic liquid (HIL), 1-decyl-3-methylimidazolium tetrafluoroborate, as the entrapping agent, was applied to facilitate the electron transfer of horseradish peroxidase (HRP) on a glassy carbon electrode. GNPs were immobilised on the TNTs in our work using a one-step reduction of HAuCl(4)·3H(2)O by sodium borohydride in the presence of sodium citrate as a stabilising reagent. The morphology and composition of the as-synthesised composite materials were characterised by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy. Cyclic voltammetry of HRP at the modified electrode presented a pair of reproducible, quasi-reversible redox peaks with a peak-to-peak separation of 69 mV, indicating electron transfer between HRP and composite electrode. The GNP-TNT|HIL|HRP electrode was then applied to the detection of H(2)O(2) in a pH 7.0 phosphate buffer using chronoamperometry. The biosensor exhibited a linear response in the 15-750 μM range, and a limit of detection of 2.2 μM. The biosensor also exhibited stability with 90% of the detection signal retained over a two-week duration.
Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, PR China.
Xiaoqiang
X
Liu
Heqing
H
Feng
Jiamei
J
Zhang
Ruoxia
R
Zhao
Xiuhua
X
Liu
Danny K Y
DK
Wong
D015374:Biosensing Techniques / Q000379:methods*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis*; D052578:Ionic Liquids / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D014025:Titanium / Q000737:chemistry*
D052578:Ionic Liquids; D006861:Hydrogen Peroxide; D014025:Titanium; D006735:Horseradish Peroxidase