Screen-Printed Glucose Sensors Modified with Cellulose Nanocrystals (CNCs) for Cell Culture Monitoring

• Main Authors: Ye Tang, Konstantinos Petropoulos, Felix Kurth, Hui Gao, Davide Migliorelli, Olivier Guenat, Silvia Generelli
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Biosensors
• Subjects: cellulose nanocrystals; amperometric glucose sensor; cell culture monitoring; screen-printed electrodes; long-term stability
• Online Access: https://www.mdpi.com/2079-6374/10/9/125

Glucose sensors are potentially useful tools for monitoring the glucose concentration in cell culture medium. Here, we present a new, low-cost, and reproducible sensor based on a cellulose-based material, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized-cellulose nanocrystals (CNCs). This novel biocompatible and inert nanomaterial is employed as a polymeric matrix to immobilize and stabilize glucose oxidase in the fabrication of a reproducible, operationally stable, highly selective, cost-effective, screen-printed glucose sensor. The sensors have a linear range of 0.1–2 mM (R² = 0.999) and a sensitivity of 5.7 ± 0.3 µA cm⁻²∙mM⁻¹. The limit of detection is 0.004 mM, and the limit of quantification is 0.015 mM. The sensor maintains 92.3% of the initial current response after 30 consecutive measurements in a 1 mM standard glucose solution, and has a shelf life of 1 month while maintaining high selectivity. We demonstrate the practical application of the sensor by monitoring the glucose consumption of a fibroblast cell culture over the course of several days.