Gold Nanoparticle-Enhanced Molecularly Imprinted Polymer Electrode for Non-Enzymatic Lactate Sensing

Area of Science:

• Electrochemistry
• Materials Science
• Biomedical Engineering

Background:

• Lactate detection is crucial for sports performance monitoring and clinical diagnostics.
• Existing enzymatic biosensors face limitations like enzyme instability and interference.
• Development of robust, non-enzymatic platforms is essential for reliable lactate monitoring.

Purpose of the Study:

• To develop a high-performance, non-enzymatic electrochemical biosensor for selective lactate detection.
• To integrate laser-induced graphene (LIG), gold nanoparticles (AuNPs), and a molecularly imprinted polymer (MIP) for enhanced sensing capabilities.
• To evaluate the sensor's performance, selectivity, and stability for practical applications.

Main Methods:

• Fabrication of a LIG electrode as a conductive scaffold.
• Electrodeposition of AuNPs onto the LIG electrode to enhance catalytic activity.
• Electropolymerization of a poly(3,4-ethylenedioxythiophene) (PEDOT)-based MIP layer for lactate-specific binding.
• Characterization using cyclic voltammetry and electrochemical impedance spectroscopy.
• Performance evaluation including linearity, sensitivity, limit of detection, selectivity, and stability in artificial saliva.

Main Results:

• The LIG/AuNPs/MIP biosensor exhibited a wide linear detection range (0.1 µM to 2500 µM).
• Achieved high sensitivity (22.42 µA/log(µM)) and a low limit of detection (0.035 µM).
• Demonstrated excellent selectivity against common interferents and high recovery rates (>95.7%) in artificial saliva, along with good long-term stability.

Conclusions:

• The developed enzyme-free electrochemical biosensor offers a robust and scalable solution for lactate monitoring.
• The integration of LIG, AuNPs, and PEDOT-MIP provides superior performance and selectivity.
• This platform holds significant potential for wearable devices in sports analytics and critical care diagnostics.