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Journal of Analytical Methods in Chemistry
Volume 2013, Article ID 687265, 5 pages
http://dx.doi.org/10.1155/2013/687265
Research Article

Label-Free Glucose Detection Using Cantilever Sensor Technology Based on Gravimetric Detection Principles

1Deparment of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung 80424, Taiwan
2Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan
3Department of Computer Science and Information Engineering, National University of Kaohsiung, Kaohsiung 81148, Taiwan

Received 31 May 2013; Accepted 14 July 2013

Academic Editor: Gangfeng Ouyang

Copyright © 2013 Shuchen Hsieh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Efficient maintenance of glucose homeostasis is a major challenge in diabetes therapy, where accurate and reliable glucose level detection is required. Though several methods are currently used, these suffer from impaired response and often unpredictable drift, making them unsuitable for long-term therapeutic practice. In this study, we demonstrate a method that uses a functionalized atomic force microscope (AFM) cantilever as the sensor for reliable glucose detection with sufficient sensitivity and selectivity for clinical use. We first modified the AFM tip with aminopropylsilatrane (APS) and then adsorbed glucose-specific lectin concanavalin A (Con A) onto the surface. The Con A/APS-modified probes were then used to detect glucose by monitoring shifts in the cantilever resonance frequency. To confirm the molecule-specific interaction, AFM topographical images were acquired of identically treated silicon substrates which indicated a specific attachment for glucose-Con A and not for galactose-Con A. These results demonstrate that by monitoring the frequency shift of the AFM cantilever, this sensing system can detect the interaction between Con A and glucose, one of the biomolecule recognition processes, and may assist in the detection and mass quantification of glucose for clinical applications with very high sensitivity.