Highly Sensitive and Selective Potassium Ion Detection Based on Graphene Hall Effect Biosensors

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Potassium ions (K⁺) are vital for cellular functions, including transmembrane potential and hormone secretion.
• Accurate K⁺ detection is crucial for health monitoring and disease diagnosis.
• Existing K⁺ detection methods face challenges in sensitivity and selectivity.

Purpose of the Study:

• To develop a highly sensitive and selective biosensor for K⁺ ion detection.
• To utilize single-layer graphene and guanine-rich DNA for enhanced K⁺ sensing.
• To explore the application of this biosensor in health monitoring.

Main Methods:

• Fabrication of a single-layer graphene biosensor.
• Immobilization of guanine-rich DNA on the graphene surface.
• K⁺ ion detection using Van der Pauw measurement configuration.

Main Results:

• Achieved a very low limit of detection for K⁺ ions (approximately 1 nM).
• Demonstrated a wide dynamic detection range (1 nM-10 μM).
• Exhibited excellent specificity for K⁺ ions over other alkali cations like Na⁺.

Conclusions:

• The developed graphene-based biosensor offers superior performance for K⁺ ion recognition.
• The guanine-quadruplex formation mechanism underlies the observed K⁺ selectivity.
• This technology holds promise for practical applications in health monitoring and early disease diagnosis.