Influence of Thermal Modification and Morphology of TiO₂ Nanotubes on Their Electrochemical Properties for Biosensors Applications

Abstract

The morphology of self-assembled TiO2 nanotubes layer plays a key role in electrical conductivity and biocompatibility properties in terms of cell proliferation, adhesion and mineralization. Many research studies have been reported in using a TiO2 nanotubes for different medical applications, there is a lack of unified correlation between TNT morphology and its electrochemical properties. The aim of this study was to examine the effects of diameter and annealing conditions on TiO2 nanotubes with identical height and their behaviour as biosensor platform. TiO2 nanotubes layer, 1000 nm thick with nanotubes of diameters in range: 25 ÷ 100 nm, was prepared by anodizing of the titanium foil in ethylene glycol solution. To change the crystal structure and improve the electrical conductivity of the semiconductive TiO2 nanotubes layer the thermal treatment by annealing in argon, nitrogen or air was used. Basing on the electrochemical tests, the XPS and scanning microscopy examinations, as well as the contact angle measurements and the amperometric detection of potassium ferricyanide, it was concluded that the 1000 nm thick TiO2 nanotubes layer with nanotubes of 50 nm diameter, annealed in argon, showed the best physicochemical properties, which helps investigate the adsorption immobilization mechanism. The possibility of using TNT as a biosensor platform was confirmed in hydrogen detection.

Electrochemical Evaluation of the Compact and Nanotubular Oxide Layer Destruction under Ex Vivo Ti6Al4V ELI Transpedicular Screw Implantation

“…The most stable potential indicated the compact Ti6Al4V before implantation, confirming the homogeneity of this layer. Oscillations seen in the course of OCP measurements of nanotubular Ti6Al4V before implantation are the results of wettability of TNT [8,9] in such a long structure. Despite this, stability in the corrosion potentials of a nanotubular Ti6Al4V ELI screw from 400 s of measurement indicates that this layer became thermodynamically stable with time.…”

“…Materials 2020, 13,176 12 of 16 circuits ( Figure 6), which represent a single-layer model-bare and compact Ti6Al4V ELI-and a bilayer model-nanotubular Ti6Al4V and the interior of the nanotubes. Identical equivalent circuits have already been used in literature for compact and nanotubular oxide layer [8,44]. The Rs element represents the uncompensated solution resistance relaxing at high frequencies.…”

“…To improve in vivo osteointegration, the Ti6Al4V ELI is subjected to surface treatments, such as nitriding, electropolishing, and electrochemical oxidation. Thermal oxidation [3] or plasma [4] is distinguished on the alloy surface from the processes of oxide layer production, but, more often, the anodic surface is subjected to anodizing [5][6][7][8]. The major advantages of the anodizing process are ability to control the fine-tuning of oxide film thickness, feature size, topography, and chemistry, as well as its simplicity, low-cost, ease of implementation, and scalability at the industrial level [6].…”

The Influence of the Parameters of a Gold Nanoparticle Deposition Method on Titanium Dioxide Nanotubes, Their Electrochemical Response, and Protein Adsorption

“…In recent decades, electrochemical biosensors have been an active research field, attracting considerable attention as potential successors to a wide range of analytical techniques with rapid response and high selectivity [1,2]. Titanium dioxide nanotube arrays have demonstrated a number of important applications, including biosensors for the detection of interleukin-6 [3] or glucose [4].…”

“…Titanium dioxide nanotube (TNT) structures can be produced through the anodization of titanium foil [5]. In addition, a recent study by the authors has shown that titanium dioxide nanotube arrays with large surface areas, easy and inexpensive preparation, and chemical and thermal stability arepromising for the immobilization of biomolecules, such as horseradish peroxidase for electrochemical biosensors [2].…”