A Calibration Strategy for Silicon Nanowire Field-Effect Transistor Biosensors and Its Application in...

Area of Science:

• Nanoscience and Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Silicon nanowire field-effect transistors (SiNW FETs) are established ultrasensitive, label-free biosensors.
• Manufacturing and surface functionalization inconsistencies lead to poor sensor-to-sensor performance consistency.
• Existing process improvements and calibration methods have yielded unsatisfactory results.

Purpose of the Study:

• To develop a novel calibration strategy for SiNW FET biosensors to overcome performance inconsistencies.
• To enhance the reliability and reproducibility of nanoscale biosensing.
• To enable rapid and ultrasensitive label-free detection of various biomolecules.

Main Methods:

• Proposed a calibration strategy combining SiNW FET sensing principles with the Langmuir-Freundlich model.
• Normalized SiNW FET biosensor response (ΔI/I₀) using their maximum saturation response (ΔI/I₀)max.
• Validated the strategy through label-free detection of nucleic acids, proteins, and exosomes.

Main Results:

• Achieved label-free detection of nucleic acids, proteins, and exosomes within 5 minutes.
• Reached detection limits as low as attomoles.
• Demonstrated a significant reduction in the coefficient of variation, improving sensor consistency.
• Observed a strong correlation (R²=0.933) between nucleic acid test results and UV-vis spectrophotometer measurements.

Conclusions:

• The proposed saturation response calibration strategy effectively addresses SiNW FET biosensor inconsistencies.
• This method offers a universal and practical approach for biological detection applications.
• Provides theoretical and experimental support for the practical application of mass-manufactured nanosensors.