Electrochemical performance and biosensor application of TiO₂nanotube arrays with mesoporous structures constructed by chemical etching

Abstract

Novel mesoporous TiO2 nanotube arrays (TiO2 NTAs) were synthesized by an anodization method combined with chemical etching in HF solution, and the electrochemical performance was studied. Glucose oxidase (GOx) was immobilized on the mesoporous TiO2 NTAs to achieve an efficient biosensor for amperometric detection of glucose. The morphology, structure, component and electrochemical performance of mesoporous TiO2 NTAs were characterized by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectrometry and an electrochemical workstation, respectively. The influence of the mesoporous structure on the electrochemical performance is discussed in detail by comparing the cyclic voltammograms and electrochemical impedance spectrum of TiO2 and mesoporous TiO2 NTAs in different conditions. High electrochemical active surface area and electron transfer rate play key roles in enhancing the electrochemical performance of mesoporous TiO2 NTAs. When used as the basis of a biosensor, the amperometric response of glucose on a GOx/TiO2-0.5 NTAs electrode is linearly proportion to the glucose concentration in the range from 0.1 to 6 mM with a sensitivity of 0.954 μA mM(-1) cm(-2), which is 14.3 times that of un-etched GOx/TiO2 NTAs.

Revealing the true impact of interstitial and substitutional nitrogen doping in TiO2 on photoelectrochemical applications

“…Over the past few decades, titanium dioxide (TiO2) solar energy harvesting devices have been widely applied in dye sensitized solar cells, sensors, photoelectrochemical (PEC) water splitting and the photocatalytic degradation of pollutants. [1][2][3][4][5][6] However, the large bandgap energy of TiO2 (anatase, E ~ 3.3 eV) limits its utilization in solar energy devices as it can be only excited in the UV region which accounts for 4 % of the solar irradiation that reaches the Earth's surface. Hence, to improve TiO2 photoelectrode performance for solar applications, absorption in the visible light spectrum must be encompassed.…”

Metal oxide nanostructures for sensor applications

“…nanotubes. The graph showed the current responses with successive injections of glucose [251]. Reproduced with permission of Elsevier, [232], [239] and [250], and Royal Society of Chemistry (2018) [251].…”

Insights into Theranostic Properties of Titanium Dioxide for Nanomedicine

“…In fact, the porous structure of TiO 2 nanotubes has a strong impact on the sensitivity of biosensors due to higher surface activity and greater electron transfer rates. The mesoporous nanostructures (glucose oxidase electrode), easily coordinate amine and carboxyl groups on the surface, behave as an electron mediator and improve the electron transfer between the redox centers of the enzymes and the electrode surface [ 199 ].…”