Electrostatic melting in a single-molecule field-effect transistor with applications in genomic identification

Area of Science:

• Bioelectronics
• Single-molecule biophysics
• Genomic identification

Background:

• Single-molecule studies are crucial for basic science and biotechnology.
• Fluorescence-based methods have signal limitations due to photon emission.
• Single-molecule field-effect transistors (smFETs) offer a bioelectronic alternative with higher signal levels.

Purpose of the Study:

• To investigate the control of biomolecular hybridization kinetics using electrostatic bias.
• To demonstrate the first single-molecule experiments utilizing electrostatics for molecular binding control.
• To explore the feasibility of detecting target DNA sequences using smFETs with electrostatic bias.

Main Methods:

• Utilized point-functionalized carbon nanotube transistors (smFETs) for intrinsic molecular charge detection.
• Applied electrostatic bias between the smFET device and the surrounding electrolyte.
• Monitored DNA hybridization kinetics and thermodynamics in response to applied bias.

Main Results:

• Demonstrated direct control over DNA hybridization kinetics via electrostatic bias.
• Achieved the first single-molecule demonstration of electrostatically controlled molecular binding.
• Successfully detected various concentrations of 20-nt Ebolavirus nucleoprotein gene target sequences at constant temperature by using bias as a temperature proxy.

Conclusions:

• Electrostatically controlled smFETs provide a powerful tool for studying and manipulating biomolecular interactions.
• This bioelectronic approach enhances signal detection for applications like genomic identification.
• The method enables controlled molecular binding detection in a constant-temperature environment, offering a new dimension for biosensing.