Challenges in Graphene-Based Biosensing: Exploring Critical Limitations and Strategies

Area of Science:

• Materials Science
• Nanotechnology
• Biosensors

Background:

• Pristine graphene offers excellent electrical and structural properties for sensing applications.
• Antigen detection is crucial for food safety and public health monitoring.

Purpose of the Study:

• To evaluate the efficacy of 1-ethyl-3-(3-(dimethylamino)propyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) chemistry for functionalizing graphene.
• To assess the reproducibility and reliability of graphene-based sensors for antigen detection.

Main Methods:

• Surface functionalization of pristine graphene using EDC-NHS coupling chemistry.
• Electrical and spectroscopic measurements (Raman spectroscopy) to characterize functionalization.
• Antigen immobilization and sensor performance evaluation for detecting penicillin and cephalexin.

Main Results:

• EDC-NHS chemistry demonstrated critical limitations in reproducibility for both electrical and spectroscopic measurements.
• Inconsistent antigen immobilization led to high variability in sensor performance.
• Raman spectroscopy indicated a lack of successful graphene surface functionalization via EDC-NHS chemistry.

Conclusions:

• The EDC-NHS coupling method is not reliable for functionalizing pristine graphene for consistent antigen detection.
• Optimizing functionalization protocols or exploring alternative surface modification techniques (e.g., defect engineering, linker molecules) is necessary.
• This study highlights challenges and offers a roadmap for improving graphene sensor reproducibility in food safety applications.