Fabricating nanoscale DNA patterns with gold nanowires

Area of Science:

• Nanotechnology
• Biomaterials Science
• Surface Chemistry

Background:

• Fabrication of nanoscale patterns is crucial for advanced applications in nanotechnology and biosensing.
• Single-stranded DNA (ssDNA) nanostructures offer potential for high-specificity bioaffinity sensing.
• Polymer substrates provide a versatile platform for creating functionalized surfaces.

Purpose of the Study:

• To develop a method for fabricating large-scale arrays of ssDNA nanolines on polymer substrates.
• To demonstrate the utility of these ssDNA nanoline arrays for specific DNA sequence detection.
• To explore the application of these patterned surfaces in bioaffinity sensing.

Main Methods:

• Fabrication of gold nanowires on glass substrates using lithographically patterned nanowire electrodeposition (LPNE).
• Transfer of biotinylated ssDNA from gold nanowires to streptavidin-coated PDMS surfaces, forming ssDNA nanolines.
• Characterization of ssDNA and resulting double-stranded DNA (dsDNA) patterns using fluorescence and atomic force microscopy (AFM).
• Detection of target ssDNA sequences using optical diffraction measurements with DNA-coated gold nanoparticles.

Main Results:

• Successfully fabricated large-scale arrays (up to 4 cm²) of ssDNA nanolines with feature sizes as small as 40 nm.
• Demonstrated successful hybridization of target ssDNA from solution onto the fabricated ssDNA nanoline arrays.
• Validated the biosensing capability by detecting unlabeled ssDNA sequences with high specificity using optical diffraction.

Conclusions:

• The developed method enables scalable fabrication of ssDNA nanoline patterns on polymer surfaces.
• These ssDNA nanoline arrays serve as a sensitive platform for bioaffinity sensing and DNA detection.
• The findings contribute to the advancement of nanotechnology and diagnostic tools for molecular recognition.