Infrared Laser Heating Applied to Nanopore Sensing for DNA Duplex Analysis

Area of Science:

• Biophysics
• Nanotechnology
• Thermodynamics

Background:

• Resistive-pulse nanopore sensing quantifies thermodynamic properties at the single-molecule level.
• Traditional bulk heating methods for nanopore sensing limit temperature control speed and optical access for complementary techniques.
• Laser-based heating, including direct infrared (IR) absorption, offers a promising alternative for enhanced temperature control.

Purpose of the Study:

• To demonstrate the efficacy of direct IR absorption heating for temperature control in biological nanopore sensing.
• To explore the measurement of DNA melting properties for short double-stranded DNA (dsDNA) homopolymers using IR-heated nanopores.
• To showcase the capability of IR heating to determine the percentage of different-sized DNA molecules in binary mixtures.

Main Methods:

• Utilized an alpha-hemolysin (α-hemolysin) biological nanopore system.
• Implemented direct infrared (IR) laser absorption for rapid, localized heating of the nanopore environment.
• Performed single-molecule resistive-pulse sensing experiments with short dsDNA homopolymers and binary DNA mixtures.

Main Results:

• Achieved rapid and precise temperature changes within and around the α-hemolysin pore using IR heating.
• Successfully quantified melting properties of short (≤50 bp) dsDNA homopolymers.
• Demonstrated the ability to accurately measure the percentage of different-sized DNA molecules in a binary mixture.

Conclusions:

• Direct IR absorption heating is an effective method for precise temperature control in nanopore sensing.
• This technique facilitates the study of single-molecule thermodynamic properties, such as DNA melting.
• IR-heated nanopore sensing offers a versatile platform for analyzing DNA properties and mixture compositions.