tio2

Bioelectrochemistry 74 (2008) 62–65

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Bioelectrochemistry j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / b i o e l e c h e m

Short communication

An electro-catalytic biosensor fabricated with Pt–Au nanoparticle-decorated titania nanotube array
Qing Kang, Lixia Yang, Qingyun Cai ⁎
State Key Laboratory of Chemo/Biosensing and Chemometrics, Department of Chemistry, Hunan University, Changsha 410082, PR China

A R T I C L E

I N F O

Article history:
Received 25 October 2007
Received in revised form 17 May 2008
Accepted 2 June 2008
Available online 12 June 2008
Keywords:
Catalytic
Titania
Nanotube array
Nanoparticle
Electrochemical

A B S T R A C T
A Gold–Platinum nanoparticle-decorated titania nanotubular electrode is fabricated by electrochemically depositing Au and Pt nanoparticles onto a highly-oriented titania nanotube array. The prepared electrode, characterized by SEM and EDX, shows remarkably improved catalytic activities in the oxidation of hydrogen peroxide. By modifying the electrode with glucose oxidase (GOx) the resultant glucose biosensor exhibits a high sensitivity to glucose in the range of 0 to 1.8 mM with a response time of 3 s and detection limit of
0.1 mM.
© 2008 Elsevier B.V. All rights reserved.

1. Introduction
Electrochemical biosensors are an active research field attracting considerable attention as potential successors to a wide range of analytical techniques with high sensitivity, rapid response and relatively high selectivity [1,2]. The sensitivity can be significantly improved by introducing metal nanoparticles into the sensing interface [1,2] to facilitate the electron transfer. Noble metals are the most researched catalysts because of their high catalytic activities in many chemical reactions [1–10]. The modification of electrode surfaces with redoxactive metal nanoparticles has led to the development of various

References: Actuators, B, Chem. 123 (2007) 1195–1205. oxygen reduction reaction, J. Power Sources 167 (2007) 243–249. Chem. 123 (2007) 495–500. [5] S. Zhao, K. Zhang, Y.Y. Sun, C.Q. Sun, Hemoglobin/colloidal silver nanoparticles immobilized in titania sol–gel film on glassy carbon electrode: Direct electrochemistry and electrocatalysis, Bioelectrochemistry 69 (2006) 10–15. [6] R. Kumara, A.N. Maitraa, P.K. Patanjalib, P. Sharma, Hollow gold nanoparticles encapsulating horseradish peroxidase, Biomaterials 26 (2005) 6743–6753. Chem. 75 (2003) 2080–2085. nanotube electrode, Talanta 71 (2007) 2040–2047. biosensor based on adsorption of glucose oxidase at platinum nanoparticlemodified carbon nanotube electrode, Anal. Biochem. 331 (2004) 89–97. Relat. Mater. 15 (2006) 433–439. Electrochim. Acta 51 (2006) 5897–5903. [14] S.F. Wang, Q. Xu, Electrochemical parameters of ethamsylate at multi-walled carbon nanotube modified glassy carbon electrodes, Bioelectrochemistry 70 (2007) [15] S.Y. Ly, Detection of dopamine in the pharmacy with a carbon nanotube paste electrode using voltammetry, Bioelectrochemistry 68 (2006) 227–231. [16] K.B. Wu, H. Wang, F. Chen, S.S. Hu, Electrochemistry and voltammetry of procaine using a carbon nanotube film coated electrode, Bioelectrochemistry 68 (2006) [18] A. Jänes, H. Kurig, E. Lust, Characterisation of activated nanoporous carbon for supercapacitor electrode materials, Carbon 45 (2007) 1226–1233. Grimes, Highly-ordered TiO2 nanotube arrays up to 220 µm in length: use in water photoelectrolysis and dye-sensitized solar cells, Nanotechnology 18 (2007) 1–11. [21] S.C. Roy, M. Paulose, C.A. Grimes, The effect of TiO2 nanotubes in the enhancement of blood clotting for the control of hemorrhage, Biomaterials 28 (2007) 4667–4672. [22] K.C. Popat, M. Eltgroth, T.J. LaTempa, C.A. Grimes, T.A. Desai, Decreased Staphylococcus epidermis adhesion and increased osteoblast functionality on antibioticloaded titania nanotubes, Biomaterials 28 (2007) 4880–4888. [23] S.Q. Liu, A.C. Chen, Coadsorption of Horseradish peroxidase with thionine on TiO2 nanotubes for biosensing, Langmuir 21 (2005) 8409–8413. Res. 18 (2003) 156–165. low concentrations, J. Nanosci. Nanotechnol. 4 (2004) 733–737. [26] H.F. Mataré, Defect Electrons in Semiconductors, Wiley-Interscience, New York, 1971.