A highly integrated sensing paper for wearable electrochemical sweat analysis

Area of Science:

• Materials Science
• Electrochemistry
• Bioengineering

Background:

• Wearable electrochemical sensors are advancing, with a focus on device integration.
• Limited attention has been given to sweat flow dynamics at human-device interfaces for continuous monitoring and comfort.
• Efficient sweat management is crucial for real-time analysis and long-term wearability of biosensors.

Purpose of the Study:

• To develop a low-cost, freestanding, and disposable highly integrated sensing paper (HIS paper) for real-time sweat analysis.
• To engineer a 3D sweat diffusion path within the HIS paper for improved sweat collection and transport.
• To create a dual-channel electrochemical sensor for simultaneous detection of glucose and lactate.

Main Methods:

• Assembled HIS paper using a simple printing process, incorporating hydrophobic wax, conducting electrodes, and MXene/methylene blue (Ti3C2Tx/MB) active materials.
• Folded the printed paper into a multi-layer structure to create a 3D sweat diffusion path.
• Designed independent 3D positioning for the three-electrode system to facilitate enzyme immobilization and electrolyte access.

Main Results:

• Achieved efficient sweat collection and diffusion along the vertical direction of the folded HIS paper.
• Demonstrated a dual-channel electrochemical sensor capable of simultaneously detecting glucose (sensitivity: 2.4 nA μM-1) and lactate (sensitivity: 0.49 μA mM-1).
• The HIS paper offers a miniaturized, low-cost, and flexible platform for wearable bioelectronics.

Conclusions:

• The developed HIS paper provides an effective solution for real-time sweat analysis in wearable bioelectronic devices.
• The unique 3D sweat diffusion design enhances sensor performance and user comfort.
• This technology presents a versatile platform for various biochemical sensing applications.