Functionalization of gold nanoparticles (AuNPs) is one of the important techniques used in production of nanomaterials and it is necessary for successful application of AuNPs arrays in catalysis, drug delivery, sensors, plasmonics and electronics. AuNPs functionalized with thiol-modified DNA strands (HS-DNA) are a well known, easily controllable, and highly adjustable product for assembling 3D nanostructures with various shapes and functions. DNA templates are widely used for controlling and measuring the distance between objects at molecular level due to its exclusive chemical structure and physical properties.

However, few reproducible and robust methods involving DNA template as a key reagent are available for obtaining anisotropic nanoparticle assemblies. It is important to...[ Read more ]

Functionalization of gold nanoparticles (AuNPs) is one of the important techniques used in production of nanomaterials and it is necessary for successful application of AuNPs arrays in catalysis, drug delivery, sensors, plasmonics and electronics. AuNPs functionalized with thiol-modified DNA strands (HS-DNA) are a well known, easily controllable, and highly adjustable product for assembling 3D nanostructures with various shapes and functions. DNA templates are widely used for controlling and measuring the distance between objects at molecular level due to its exclusive chemical structure and physical properties.

However, few reproducible and robust methods involving DNA template as a key reagent are available for obtaining anisotropic nanoparticle assemblies. It is important to strictly control the number and location of DNA strands on the AuNPs surface. In this thesis, we introduce an efficient approach for surface functionalization of AuNPs using unmodified DNA oligonucleotides by building DNA cages that trap nanoparticles. Edges of a DNA cage are used for positioning functional oligonucleotides for further application of obtained asymmetrically finctionalized AuNPs in various DNA circuits for nucleic acid detection and nanostructure assembly.

This enabled us to vary the process of nanoassembly, and create anisotropic nanoparticles that are necessary for directed structure construction without involving DNA origami approach. The developed method simplifies production process in comparison with conventional HS-DNA modification protocols and helps to precisely control the density and position of functional DNA strands designed for further hybridization with other AuNP conjugates. In this work we developed a protocol for direct module assembly of nanostructures that can be applied for nucleic acid detection. The method was validated to be robust in DNA circuits and nucleic acid delivery into cell culture.