Introduction of Functional Groups

"Introducing functional groups into nanoparticles," also known as "surface functionalization," is a process where specific chemical groups are added to the surface of nanoparticles to modify their chemical properties, enhance their reactivity, control solubility, improve stability, or facilitate interactions with biological molecules. These functional groups play a crucial role in determining the behavior of nanoparticles in various applications, such as drug delivery, biosensing, catalysis, and electronics.

Common Functional Groups

• Hydroxyl (-OH): Increases hydrophilicity and can form hydrogen bonds, enhancing interactions with biological molecules.
• Carboxyl (-COOH): Provides increased solubility and can serve as a site for further reactions or binding with biomolecules.
• Amino (-NH2): Often used in bioconjugation and can react with various compounds, enhancing cell targeting.
• Thiol (-SH): Strongly binds with metal surfaces and can stabilize nanoparticles while allowing for the conjugation of other molecules.
• Aldehyde (-CHO): Can react with amine groups on biomolecules, providing a platform for targeted drug delivery.
• Phenyl (-C6H5)**: Provides hydrophobic characteristics and can participate in π-π stacking interactions with other aromatic structures.
• Phosphate (-PO4): Can enhance the bioactivity of nanoparticles, especially in applications related to drug delivery and gene therapy.
• Alkyl chains (e.g., -C8H17): Introduced to enhance hydrophobic interactions or for creating self-assembled monolayers.
• Silane groups (R-Si (OR')3): Often used in surface modifications for silica nanoparticles, promoting bonding to various substrates.

The choice of functional groups depends on the intended application of the nanoparticles, the desired interactions with biological systems or other materials, and the need for biocompatibility or specificity.

Common Functionalization Methods

• Physical Adsorption: Physical adsorption relies on non-covalent interactions, such as van der Waals forces, hydrogen bonding, and electrostatic forces to attach functional groups to nanoparticle surfaces.
  • Langmuir and Freundlich adsorption
  • Simple electrostatic assembly
  • Hydrophobic interaction
• Chemical Modification: Chemical modification involves covalent bonding or the introduction of specific functional groups onto the nanoparticle surfaces.
  • Silane Coupling
  • Grafting
  • Self-Organizing Monolayers (SAMs)
  • Click Chemistry

STEMart provides service to introduce suitable functional groups to the surface of the nanoparticles, either to improve the stability or enhance the compatibility with other materials for nano-enabled products or to facilitate targeting and modulate protein corona formation for biomedical applications. For more information about our nanoparticle surface functionalization service, please contact us.