Optimizing Surface Functionalization for Aptameric Graphene Nanosensors in Undiluted Physiological Media.

Area of Science:

• Biosensors
• Nanotechnology
• Surface Chemistry

Background:

• Graphene nanosensors offer signal transduction for biomarker detection.
• Nonspecific adsorption of matrix molecules hinders sensor performance in physiological media.
• Surface modification is crucial for optimizing aptameric nanosensor functionality.

Purpose of the Study:

• Optimize surface modification of aptameric graphene nanosensors.
• Enhance sensor performance for biomarker measurement in undiluted physiological media.
• Systematically study the impact of attachment schemes and parameters on sensor behavior.

Main Methods:

• Systematic study of aptamer and polyethylene glycol (PEG) attachment schemes.
• Evaluation of PEG molecular weight, surface density, and aptamer surface density.
• Testing sensor responsivity and rejection of nonspecific binding in physiological media.

Main Results:

• Identified optimal graphene nanosensor designs for biomarker responsiveness and reduced nonspecific adsorption.
• Demonstrated sensitive and specific measurement of C-reactive protein (CRP) in undiluted human serum.
• Achieved a limit of detection (LOD) down to 27 pM for CRP, a significant improvement over previous methods.

Conclusions:

• Optimized surface modification enables sensitive and specific biomarker detection in complex biological samples.
• The developed aptameric graphene nanosensors show great promise for clinical diagnostics.
• Serial modification with specific PEG and aptamer parameters yields superior sensor performance.