Anodic Functionalization of Titania Nanotube Arrays for the Electrochemical Detection of Tuberculosis Biomarker Vapors

Abstract

Anodic titania nanotube arrays have been extensively explored for gas sensing applications due to their high chemical and thermal stability and robust synthesis method. In this study, we explore the use of functionalized titania nanotube arrays for the electrochemical detection of gaseous volatile organic biomarkers associated with tuberculosis. The synthesis method developed allows for in situ functionalization of titania nanotubes with oxygen containing metal species (i.e., Co(OH)2) during anodization. Amperometric detection of volatile organic biomarkers with concentrations of 275 ∼ 360 ppm using next generation titania nanotubes functionalized with Co(OH)2 where compared with Co(OH)2 functionalized titania nanotubes via a wet incipient method. Improved sensor response and sensitivity was observed with next generation titania nanotubes, which can be attributed to homogeneous distribution of reactive sites directly in contact with the parent titania. A mechanism for sensor response and in situ functionalization is presented.