Immobilization of different biomolecules by atomic force microscopy.

Area of Science:

• Biotechnology
• Nanotechnology
• Surface Chemistry

Background:

• Precise placement of probe molecules is crucial for biochip and lab-on-chip systems.
• Existing methods for immobilizing multiple substances are often expensive and limited.
• A flexible procedure for simultaneous, spatially controlled immobilization of biomolecules using molecular ink lithography is presented.

Purpose of the Study:

• To develop a universal, high-resolution method for immobilizing diverse biomolecules.
• To enable bottom-up fabrication of surface-bound nanostructures with arbitrary arrangements.
• To overcome limitations of current methods in depositing multiple probe types.

Main Methods:

• Biotinylation of a supporting surface followed by atomic force microscope (AFM) tip deposition of streptavidin at specific positions.
• Subsequent incubation with biotinylated molecules for binding at deposited streptavidin sites.
• Repetitive deposition of streptavidin and different biotinylated molecules for multi-analyte arrays, performed in situ.

Main Results:

• Demonstrated immobilization of different biomolecules (DNA, proteins) with micrometer resolution (<400 nm).
• Achieved arbitrary arrangements of multiple biomolecule types, unlike methods limited to a single probe type.
• Method validated on transparent and opaque substrates using DNA hybridization and fluorescence microscopy.

Conclusions:

• The developed molecular ink lithography enables high-density microarray fabrication with submicrometer resolution.
• This technique is applicable to various biomolecules, including DNA and proteins, that can be biotinylated.
• Offers a flexible and versatile solution for advanced biotechnology applications.