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

摘要

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-termtherapeutic practice. In this study, we demonstrate amethod 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 firstmodified theAFMtip with aminopropylsilatrane (APS) and then adsorbed glucose-specific lectin concanavalin A(ConA) onto the surface.The Con A/APS-modified probeswere then used to detect glucose by monitoring shifts in the cantilever resonance frequency. To confirmthe 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, andmay assist in the detection andmass quantification of glucose for clinical applications with very high sensitivity.