Boron-doped diamond solution-gate field-effect transistor (BDD-SGFET) biosensor for gene mutation detection

Area of Science:

• Biosensor technology
• Nanomaterials
• Molecular diagnostics

Background:

• Gene mutations are key drivers of major diseases.
• Accurate detection of DNA base mismatches is crucial for biological and clinical applications.
• Existing methods for genetic mutation analysis can be complex and time-consuming.

Purpose of the Study:

• To develop a high-performance boron-doped diamond solution-gated field-effect transistor (BDD-SGFET) biosensor.
• To enable label-free detection of base mismatches in EGFR gene mutations.
• To assess the potential of microscale BDD-SGFETs for point-of-care genetic testing.

Main Methods:

• Device fabrication using microwave plasma chemical vapor deposition (MPCVD), photolithography, and plasma etching.
• Design optimization of diamond microwire dimensions for enhanced electrical properties.
• Performance evaluation including transconductance, threshold voltage, limit of detection, and anti-interference capabilities.

Main Results:

• Fabricated BDD-SGFETs with microwire structures exhibited high performance.
• Achieved a limit of detection as low as 10 pM.
• Successfully identified DNA molecules with two base-pair mismatches.
• Demonstrated excellent anti-interference properties and stability in complex environments.

Conclusions:

• Microscale BDD-SGFETs offer a promising platform for rapid, label-free genetic mutation analysis.
• The developed biosensor shows significant potential for point-of-care testing in cancer diagnosis.
• Optimized device design enhances sensitivity and robustness for clinical applications.