Electrochemical impedance response of the nanostructured Ti–6Al–4V surface in the presence of S. aureus and E. coli

Abstract

Implant infections associated with biofilm are a significant problem in current healthcare. Early detection of the development of bacterial infection would allow the deployment of antibiotic treatment to suppress complications. Biofilm detection can be based on the changes in the electrochemical response of a metal oxide sensor. The nanostructured surface of titanium alloys provides a large active/geometric surface area ratio and may respond to the presence of bacteria by changing its behaviour. In this work, the changes in impedance response of nanostructured Ti–6Al–4V alloy surface in the presence of E. coli and S. aureus were studied. The nanostructures were prepared by anodic oxidation in a fluoride ions-containing environment. The change in impedance spectra and open circuit potential of the prepared surfaces was monitored for 48 h. Furthermore, a series of measurements in model systems were carried out to help identify the processes leading to the change in the electrochemical behaviour of the surface. The measurements showed significant changes in the surface impedance response over a wide range of frequencies and for both bacterial strains. Based on the results, the implantable sensor based on the nanotubular titanium oxide seems to be a possible and simple way how to detect bacterial infection. Graphical Abstract

Preparation, Characterization and Electrochemical Response of Nanostructured TiAlV with Potentiostatically Deposited IrOx as a pH Sensor for Rapid Detection of Inflammation

“…The length of the nanotubes was then determined from the TEM image (Figure 5c). These results correspond with those of previously published works [27,31]. Figure 5a shows Ir PS and Figure 5b displays Ir PS+CP samples.…”

“…The length of the nanotubes was then determined from the TEM image (Figure 5c). These results correspond with those of previously published works [27,31]. Figure 6 shows the TEM-EDS map of the iridium distribution in the lamella obtained from the (a) Ir PS and (b) Ir PS+CP samples.…”

“…A nanotubular TiO 2 structure was formed on the Ti-6Al-4V surface by anodic oxidation in a fluoride solution. This procedure was consistent with published procedures [26,27]. The surface morphology is shown in Figure 1.…”

“…Compared to previously published works [11,[17][18][19]25,29,30], our presented IrO 2 deposition procedure achieves a reproducible and uniform distribution of particles on the surface of the titanium substrate. By not sealing the nanotubes with Ir particles, the purpose of nanotube formation is preserved, namely to increase the real area compared to the geometric one and maintain the ability to direct biofilm formation detection [27].…”