pH effects on BSA-dispersed carbon nanotubes studied by spectroscopy-enhanced composition evaluation techniques

Area of Science:

• Materials Science
• Analytical Chemistry
• Biochemistry

Background:

• Dispersion of carbon nanotubes (CNTs) using water-soluble agents like proteins is crucial for their application in composites and biomedical fields.
• Separation of dispersed CNTs from impurities and dispersants yields complex solutions with overlapping spectral signals.
• Existing methods for quantifying CNTs and dispersants, such as visual inspection or single-wavelength UV-visible measurements, lack accuracy and simplicity.

Purpose of the Study:

• To develop and apply chemometric techniques for accurate quantification of single-wall carbon nanotubes (SWNTs) and bovine serum albumin (BSA) in aqueous solutions.
• To investigate the influence of pH on the dispersion efficiency and concentration of SWNTs and BSA.
• To establish a reliable method for analyzing complex CNT-dispersant mixtures.

Main Methods:

• Utilized chemometric analysis combined with full UV-visible spectroscopy to deconvolve overlapping signals from SWNTs and BSA.
• Investigated the effect of varying pH on the spectral properties and concentrations of SWNTs and BSA in solution.
• Correlated spectral data with protein conformation to understand dispersion mechanisms.

Main Results:

• Successfully quantified concentrations of both SWNTs and BSA in aqueous solutions by analyzing full UV-visible spectra.
• Demonstrated a strong correlation between the conformational state of BSA and its efficiency in dispersing SWNTs.
• Identified pH as a critical factor influencing protein conformation and subsequent dispersion performance.

Conclusions:

• Chemometric analysis of UV-visible spectra provides an accurate and simple tool for quantifying SWNTs and dispersants like BSA.
• Protein conformation significantly impacts CNT dispersion efficiency, offering insights for optimizing suspension stability.
• This method advances the reliable characterization of nanomaterial suspensions for diverse applications.