Well-Aligned TiO 2 Nanotube Arrays with Ag Nanoparticles for Highly Efficient Detection of Fe 3+ Ion

Nowadays, determination of the iron ions with high sensitivity and selectivity with novel methods becomes a matter of urgency for monitoring healthy body and environment. In this paper, for the first time, we present a set of high-performance TiO 2 nanotube arrays which are quite sensitive to iron ions. Firstly, the anodic oxidation method was adopted to prepare ordered TiO 2 nanotube arrays, followed by functionalized Ag nanoparticle deposition with the enhancement ability in iron ion sensing. Besides, the spectrum of the TiO 2 nanotube with/without the Ag nanoparticles was analyzed with an X-ray photoelectron spectrometer, which shows that Ag nanoparticles can effectively reduce the recombination rate of electrons and holes, and increase the conductivity and the charge transfer rate of the electrodes. Further, when functionalized Ag nanoparticles on well-ordered TiO 2 nanotube arrays were used, iron ion sensing performed with the anodic stripping voltammetry method was investigated to validate the great potential of TiO 2 nanotube arrays with a sensitivity of approximately 30 μA/ug/L in becoming Fe 3+ sensors. This method creates new possibilities for developing sensors for monitoring of Fe 3+ in biological samples without any sample pretreatment procedure.