A simple method for the quantification of molecular decorations on silica particles

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Accurate quantification of surface functionalization is crucial for controlling nanoparticle properties.
• Existing methods for determining attachment density can be time-consuming or lack precision.
• Silica nanoparticles are widely used in various applications, necessitating precise surface modification.

Purpose of the Study:

• To develop a simple, rapid, and quantitative method for determining attachment density on silica nanoparticles.
• To achieve high surface functionalization of silica nanoparticles using a photoinduced thiol-ene click reaction.
• To explore the controlled synthesis of functionalized and multifunctional nanoparticles.

Main Methods:

• Utilized attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) for quantitative analysis of attachment density.
• Verified the results obtained from ATR-FTIR using thermogravimetric analysis (TGA).
• Employed a photoinduced thiol-ene click reaction between 11-bromo-1-undecene and thiol-functionalized silica nanoparticles.

Main Results:

• Demonstrated a simple and rapid quantitative method for determining attachment density on silica nanoparticles.
• Achieved a high attachment density of approximately 5 attachments per nm² on silica nanoparticles.
• Observed a highly nonlinear relationship between attachment density and alkene concentration/reaction time, suggesting accessibility limitations of surface thiols.

Conclusions:

• The developed ATR-FTIR method provides a fast and accurate way to quantify nanoparticle surface functionalization.
• High surface functionalization of silica nanoparticles is achievable via photoinduced thiol-ene click chemistry.
• This approach enables the controlled synthesis of nanoparticles with tailored functionalities, including multifunctional particles.