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

Abstract

The goal of this research was to find the best conditions to prepare titanium dioxide nanotubes (TNTs) modified with gold nanoparticles (AuNPs). This paper, for the first time, reports on the influence of the parameters of cyclic voltammetry process (CV) -based AuNP deposition, i.e., the number of cycles and the concentration of gold salt solution, on corrosion resistance and the capacitance of TNTs. Another innovation was to fabricate AuNPs with well-formed spherical geometry and uniform distribution on TNTs. The AuNPs/TNTs were characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and open-circuit potential measurement. From the obtained results, the correlation between the deposition process parameters, the AuNP diameters, and the electrical conductivity of the TNTs was found in a range from 14.3 ± 1.8 to 182.3 ± 51.7 nm. The size and amount of the AuNPs could be controlled by the number of deposition cycles and the concentration of the gold salt solution. The modification of TNTs using AuNPs facilitated electron transfer, increased the corrosion resistance, and caused better adsorption properties for bovine serum albumin.

Comparison of Gold Nanoparticles Deposition Methods and Their Influence on Electrochemical and Adsorption Properties of Titanium Dioxide Nanotubes

“…According to reference [ 29 ] the standard of the peak of Ti 2p3/2 in TiO 2 for Ti 3+ is located at 457.7 eV, while for Ti 4+ is at 459.5 eV. The O 1s peak for TiO 2 is located 529.3 eV [ 22 , 29 , 30 ]. Analysis of the values presented in Table 1 shows that the smaller amount of oxygen at the surface (at 8.8%) and higher amountof oxygen inside the oxide film (lattice oxygen–at 47.1%) was observed.…”

“…In our studies, due to the charge of surface, we used electrostatic interactions. According to the author’s previous studies [ 22 ], the AuNPs in PBS solution have positive charge value. According to Table 2 , the surface charge of TNTs is equal to −47 ± 7.2 mV.…”

“…The deposition process was carried out 40 cycles and different concentrations of HAuCl 4 . The choice of the number of deposition for cycles was justified in the authors’ previous publication [ 22 ]. The AuNPs/TNTs for which deposition was carried out for 40 cycles had the positive value of OCP, one of the lowest values of SD (standard deviations), impedance modulus and time constant.…”

“…In turn, the use of cyclic voltammetry [ 19 , 20 ] and chronoamperometry [ 21 ] greatly simplify the process of modifying the TNTs platform. The authors’ earlier work showed the possibility of controlling the AuNPs morphologic parameters (diameter in the range of 20.3 ± 2.9 to 182.3 ± 51.7 nm) by choosing parameters of the CV process [ 22 ]. To date, there is no clear indication in the literature concerning the effect of time of the chronoamperometric method on the size and amount of AuNPs deposited on TiO 2 nanotubes surface.…”

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

“…Implantation causes a decrease in phase angle value and impedance modulus, both for compact and nanotubular Ti6Al4V. Higher phase angle values recorded for nanotubular Ti6Al4V are the result of a higher affinity to phosphate absorbing by titanium dioxide nanotubes [28,42,43]. Therefore, as can be seen in Table 4, the larger capacitive semicircle diameters and the increased phase angle all imply that a more protective passive layer was obtained on the nanotubular Ti6Al4V.…”