In Situ Functionalized MXene on Porous Laser-Induced Graphene for Adsorption-Dominated Miniaturized Multifunctional...

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Wearable sensors face challenges in sensitivity and stability upon miniaturization.
• MXene materials, while promising, suffer from oxidation and reduced performance in small-scale applications.

Purpose of the Study:

• To develop a highly stable and sensitive nanocomposite for miniaturized wearable sensors.
• To shift electrochemical reactions from diffusion-controlled to adsorption-controlled for improved performance.
• To address oxidation issues in MXene for enhanced sensor longevity.

Main Methods:

• A two-step direct laser writing process was employed.
• MXene with reduced surface terminating groups was functionalized *in situ* on laser-induced graphene foam.
• The electrochemical reaction mechanism was altered to be adsorption-controlled.

Main Results:

• The electrochemical sensor demonstrated a significant increase in sensitivity to glucose (from 242.78 to 2751.3 μA/mM·cm²).
• A low limit of detection (0.3 μM), rapid response time (0.1 s), and excellent stability (35 days) were achieved.
• The nanocomposite showed potential for humidity sensing and dry electrophysiological electrodes, even with sweat.

Conclusions:

• The developed nanocomposite offers enhanced sensitivity, stability, and miniaturization capabilities for wearable health monitoring.
• The sensor's versatility extends to humidity and electrophysiological sensing.
• Integration into devices like VR masks enables comprehensive physical and mental health monitoring.