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Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods
Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-60174 Norrköping, Sweden
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Received: 22 September 2009; in revised form: 19 October 2009 / Accepted: 19 October 2009 / Published: 9 November 2009
Abstract: ZnO nanotubes and nanorods grown on gold thin film were used to create pH sensor devices. The developed ZnO nanotube and nanorod pH sensors display good reproducibility, repeatability and long-term stability and exhibit a pH-dependent electrochemical potential difference versus an Ag/AgCl reference electrode over a large dynamic pH range. We found the ZnO nanotubes provide sensitivity as high as twice that of the ZnO nanorods, which can be ascribed to the fact that small dimensional ZnO nanotubes have a higher level of surface and subsurface oxygen vacancies and provide a larger effective surface area with higher surface-to-volume ratio as compared to ZnO nanorods, thus affording the ZnO nanotube pH sensor a higher sensitivity. Experimental results indicate ZnO nanotubes can be used in pH sensor applications with improved performance. Moreover, the ZnO nanotube arrays may find potential application as a novel material for measurements of intracellular biochemical species within single living cells.
Keywords: ZnO nanotubes; ZnO nanorods; pH sensors; potentiometric measurements
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MDPI and ACS Style
Fulati, A.; Usman Ali, S.M.; Riaz, M.; Amin, G.; Nur, O.; Willander, M. Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods. Sensors 2009, 9, 8911-8923.
Fulati A, Usman Ali SM, Riaz M, Amin G, Nur O, Willander M. Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods. Sensors. 2009; 9(11):8911-8923.
Fulati, Alimujiang; Usman Ali, Syed M.; Riaz, Muhammad; Amin, Gul; Nur, Omer; Willander, Magnus. 2009. "Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods." Sensors 9, no. 11: 8911-8923.