Label-free DNA sensing platform with low-voltage electrolyte-gated transistors

Area of Science:

• Materials Science
• Biotechnology
• Electrical Engineering

Background:

• Developing portable biosensors for DNA detection is crucial for point-of-care diagnostics and field applications.
• Existing methods for DNA hybridization detection often require complex instrumentation or are not easily miniaturized.
• Electrolyte-gated transistors (EGTs) offer a promising platform for sensitive and label-free biosensing due to their high gain and low operating voltage.

Purpose of the Study:

• To develop a novel potentiometric method for measuring DNA hybridization.
• To create a portable or hand-held biosensor for DNA detection.
• To demonstrate the feasibility of using an electrolyte-gated transistor (EGT) as a transducer for surface DNA hybridization.

Main Methods:

• Fabrication of an electrolyte-gated transistor (EGT) using poly(3-hexylthiophene) (P3HT) and an ion-gel.
• Functionalization of a floating-gate electrode with single-stranded DNA (ssDNA).
• Measurement of potential shifts in the P3HT semiconductor due to DNA hybridization at the floating gate.

Main Results:

• The EGT-based sensor demonstrated a measurable potential offset upon DNA hybridization.
• The measured potential offset was quantitatively related to the number density of double-stranded DNA (dsDNA) molecules.
• The sensing strategy showed potential for adaptation to other biomolecules and integration into microfluidic systems.

Conclusions:

• A novel potentiometric method for DNA hybridization detection using P3HT-based EGTs has been successfully developed.
• The developed biosensor is conducive to portable and hand-held applications.
• The sensing strategy is versatile and can be extended to detect other biomolecules for diverse field applications.