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

Ewa Paradowska,Dorota G Pijanowska,Katarzyna Arkusz

doi:10.3390/bios9040138

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.

Highlights

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]
For the purpose of this study, the electrochemical parameters of titanium dioxide nanotubes with a diameter of 50 ± 5 nm and height of 1000 ± 100 nm, annealed at 450 ◦ C in argon atmosphere for 2 h before and after deposition of gold nanoparticles using cyclic voltammetry
The titanium dioxide nanotubes (TNTs) arrays with diameter of 50±5 nm and height of 1000 ± 100 nm had smooth walls without any perforation and were uniformly arranged on the titanium foil

Summary

Introduction

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]. 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]. The electric conductive and adsorption properties of TNT arrays depend on many factors, e.g., the morphology of the nanotubes (diameter, height) and the modification process. The electrical conductivity of TNT arrays can be significantly improved by introducing metal nanoparticles to the surface to facilitate electron transfer [1,7,8,9].

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