Preparation Of Titanium Dioxide Nanotube Arrays Composite Nanomaterials For Electrochemical Sensors

Highly sensitive and selective electrochemical sensors have been intensively studied recently.The emerging nanomaterials and nanotechnologies have paved the way for the development of high performance electrochemical sensors.Electrochemically anodized titanium dioxide nanotube arrays?TiO₂ NTAs?possess uniform nanostructure,high specific surface area,good chemical stability and excellent biocompatibility.This nanomaterial has been demonstrated the ideal substrate to develop nanostructured electrochemical sensors.Herein,we reported a high performance electrochemical sensor by coating a carbon layer on TiO₂ NTAs to form a core-shell TiO₂-C nanotube arrays?TiO₂@C NTAs?.The TiO₂@C NTAs were futher decorated with copper and nickel nanoparticles to develop glucose sensors.The main contributions of this dissertation are summerized as follows:?1?Uniform TiO₂ NTAs were fabricated by electrochemical anodization,with tube diameters of ⁸0 nm,lengths ranging from 3 to 5?m.A carbon layer was coated on TiO₂ NTAs by hydrothermal treatment of TiO₂ NTAs in glucose solution,followed by annealing in a tube furnace under argon flow.The TiO₂@C NTAs electrode exhibits a reversible voltammetric response to {Fe?CN?6}3-/4-redox couple and can be applied to the determination of some small biological molecules such as dopamine?DA?,ascorbic acid?AA?and uric acid?UA?.Selective detection of DA was demonstrated with coexistence of AA and UA,exhibiting a linear range of 1-100 ?M by differential pulse voltammetry.?2?Copper nanoparticles decorated TiO₂@C NTAs?Cu NPs/TiO₂@C NTAs?were prepared by hydrothermal treatment of TiO₂@C NTAs in Cu?NO3?2 solution.Cu NPs were uniformly dispersed in the nanotubes of TiO₂@C NTAs.The Cu NPs/TiO₂@C NTAs sensor was employed for the determination of glucose,with a sensitivity of 1157?A·mM-1·cm-2,a linear range of 1-2467 ?M,a detection limit of 0.17 ?M?S/N=3?,a good reproducibility with a relative standard deviation?RSD?of 3.3%?n=10?andminimal interferences from coexistence species in serum.The NPs/TiO₂@C NTAs sensor was successfully applied to the detection of glucose in human serum,indicating a promising glucose sensor for clinical applications.?3?Nickel nanoparticles decorated TiO₂@C NTAs?Ni NPs/TiO₂@C NTAs?were prepared by hydrothermal treatment of TiO₂@C NTAs in NiSO4 solution.The Ni NPs/TiO₂@C NTAs sensor was applied to the determination of glucose,with a sensitivity of 182.72 ?A·mM-1·cm-2,a linear range of 11-4986 ?M,a detection limit of13.4 ?M?S/N=3?,a good reproducibility with a relative standard deviation?RSD?of6.8%?n=10?and minimal interferences from coexistence species such as AA and UA in serum.