Multisite Dopamine Sensing With Femtomolar Resolution Using a CMOS Enabled Aptasensor Chip.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Biosensors

Background:

• Biomarkers in external fluids (sweat, saliva) are crucial for diagnostics but present at low concentrations.
• Sensitive and minimally invasive detection methods are needed for analyzing these biomarkers.
• Existing techniques often lack the required sensitivity or miniaturization for point-of-care applications.

Purpose of the Study:

• To develop a robust biosensing platform for high-sensitivity detection of biomarkers in bodily fluids.
• To integrate silicon nanowire field-effect transistors (SiNW SJ-FETs) with CMOS electronics for a miniaturized diagnostic system.
• To demonstrate selective and multi-site detection of neurotransmitters like dopamine.

Main Methods:

• Hybrid integration of bottom-up silicon-nanowire Schottky-junction FETs (SiNW SJ-FETs) with CMOS readout and amplification electronics.
• Development of a 32x32 aptasensor array with a 100-micrometer pitch.
• Utilizing heterojunctions for selective biomolecular detection.

Main Results:

• Achieved selective biomolecular detection down to femtomolar concentrations.
• Demonstrated selective and multi-site detection of dopamine with an exceptional sensitivity of approximately 1 V/fM.
• The integrated platform successfully detected biomarkers at high dilution levels.

Conclusions:

• The developed hybrid biosensing platform offers high sensitivity and miniaturization for minimally invasive diagnostics.
• Potential applications include early diagnosis of neurodegenerative diseases and monitoring therapeutic progress using samples like tears, saliva, or sweat.
• This technology advances the field of point-of-care diagnostics for a range of health conditions.