Titanium dioxide-cellulose hybrid nanocomposite based conductometric glucose biosensor Mohammad Maniruzzaman, Suresha K. Mahadeva, Abu Hasan Khondhoker, Jaehwan Kim * Creative Research Center for EAPap Actuator, Dept. of Mechanical Engineering, Inha University, Incheon 402-751, South Korea ABSTRACT This paper investigates the feasibility of conductometric glucose biosensor based on glucose oxidase (GOx) immobilized TiO 2 -cellulose hybrid nanocomposite. TiO 2 nanoparticles were blended with cellulose solution prepared by dissolving cotton pulp with lithium chloride/N, N-dimethylacetamide solvent to fabricate TiO 2 -cellulose hybrid nanocomposite. The enzyme (GOx) was immobilized into this hybrid material by physical adsorption method. The successful immobilization of GOx into TiO 2 -cellulose hybrid nanocomposite via covalent bonding between TiO 2 and GOx was confirmed by X-ray photoelectron analysis. The linear response of our propose glucose biosensor is obtained in the range of 1-10mM with correlation coefficient of 0.93. Our study demonstrates TiO 2 -cellulose hybrid material as a potential candidate for an inexpensive, flexible and disposable glucose biosensor. Keywords: Titanium dioxide, Cellulose, Glucose biosensor, Conductometric, Glucose oxidase. 1. INTRODUCTION Inorganic-organic nanocomposites form an attractive new class of functional hybrid nanocomposite that demonstrates improved optical, thermal and mechanical properties due to synergistic effects resulting from the physical or chemical interactions which occur between the inorganic and organic elements [1]. Cellulose is the most abundant natural polymer in the world, which can be regenerated or derivatized to produce numerous useful products due to its renewability, biodegradability and bio-compatibility [2, 3]. Recently, enormous work has been reported on cellulose based hybrid nanocomposite [3]. On other hand, titanium dioxide (TiO 2 ) is a wide band gap semiconducting material which has recently attracted much interest due to its broad range of chemical and physical properties including chemical stability, electrical conductivity, photocatalytic activity and photosensitivity [4]. Thus, a combination of TiO 2 and cellulose can be a potential hybrid nanocomposite by offering a unique property of cellulose in conjunction with electrical property of TiO 2 . Since Clark and Lyons introduced the initial concept of glucose enzyme electrodes in 1962 [5], enormous attentions have been paid to develop a reliable device (biosensor) to monitor blood glucose level for diabetes control. Recently polymer- metal oxide hybrid material based glucose biosensors have become an increasing trend. Wang et al. have developed a glucose biosensor based on organic-inorganic hybrid material [6]. They reported hybrid material comprising of silica sol and a grafting copolymer of poly (vinyl alcohol) with 4-vinylpyridine as a glucose biosensor, which has high sensitivity (600 nA mmol -1 L -1 ), short response time (11s) and long-term stability. Choi et al. have developed a glucose biosensor made with metal oxide/Nafion composite films [7]. They addressed that the performance of the glucose biosensor based on TiO 2 /Nafion is better than that of SiO 2 /Nafion in terms of response time, sensitivity and stability. Tin oxide/cellulose hybrid nanocomposite has recently been employed as a conductometric glucose biosensor [8]. The linear response of the glucose biosensor was in the range of 0.5-12 mM of glucose. In this paper we report a feasibility study of TiO 2 -cellulose hybrid nanocomposite based conductometric glucose biosensor. The fabrication processes of TiO 2 -cellulose hybrid nanocomposite and the glucose biosensor are addressed. The electrical conductivity of the glucose biosensor was measured to determine the enzyme activity of the biosensor. Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2012, edited by Vijay K. Varadan, Proc. of SPIE Vol. 8344, 83440J · © 2012 SPIE · CCC code: 0277-786X/12/$18 · doi: 10.1117/12.915759 Proc. of SPIE Vol. 8344 83440J-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 01/13/2015 Terms of Use: http://spiedl.org/terms