Multilayer patch functionalized microfibrillated cellulosic paper sensor for sweat glucose monitoring

Area of Science:

• Biomaterials Science
• Biosensors
• Analytical Chemistry

Background:

• Current glucose monitoring methods often involve painful blood collection.
• There is a need for noninvasive, accurate glucose monitoring solutions.
• Diabetes mellitus management requires continuous and convenient glucose level tracking.

Purpose of the Study:

• To develop a novel biobased cellulosic paper sensor for noninvasive glucose monitoring.
• To enhance sensor performance through functionalization and innovative design.
• To create a closed-loop system for diabetes management using sweat analysis.

Main Methods:

• Functionalization of microfibrillated cellulose (MFC) with hexokinase-mediated phosphorylation to enhance hydrophilicity.
• Development of methylated and phosphorylated cellulosic paper-based glucose sensors.
• Integration of the sensor into a multilayer patch with artificial transdermal drug delivery for sweat collection and analysis.
• Testing the sensor's accuracy under varying sweat volumes, temperatures, and pH levels.

Main Results:

• Functionalized MFC paper exhibited increased hydrophilicity, confirmed by higher surface charge density and lower contact angle.
• The sensor required only 1 µl of sweat for accurate glucose analysis.
• Methyl groups provided a barrier against interfering chemicals.
• The multilayer patch design improved sweat collection and sensing efficiency.
• The integrated system demonstrated accurate glucose monitoring across a range of sweat volumes (1-4 µl), temperatures (20-70 °C), and pH (4.0-7.0).
• The 'switch system' showed accurate measurement of drug delivery, correlating with sensor accuracy.

Conclusions:

• The developed MFC paper-based sensor offers a promising noninvasive approach for glucose monitoring.
• The disposable multi-patch sensing system provides a novel closed-loop solution for diabetes mellitus management.
• This technology eliminates the need for painful blood collection, improving patient compliance and quality of life.