Quantification of Amino Groups on Solid Surfaces Using Cleavable Fluorescent Compounds.

Area of Science:

• Surface Chemistry
• Analytical Chemistry
• Biomaterials Science

Background:

• Quantifying surface functional groups is crucial for material characterization and applications.
• Existing methods may lack sensitivity or specificity for certain surface types.
• Amino groups are key for immobilizing ligands and biomolecules onto surfaces.

Purpose of the Study:

• To develop and validate a sensitive method for quantifying amino groups on inorganic and organic surfaces in aqueous solutions.
• To identify the most suitable cleavable fluorescent compound for amino group quantification.
• To assess the method's ability to detect surface-accessible amino groups for biomolecule immobilization.

Main Methods:

• Utilized various cleavable fluorescent compounds and an aldehyde dye for amino group quantification.
• Investigated the covalent binding of fluorescent probes to amino groups.
• Determined the optimal conditions for cleaving fluorescent compounds to release signals.
• Assessed quantification on silica and resin surfaces.

Main Results:

• Cleavable coumarin demonstrated superior performance for quantifying amino groups on silica and resin surfaces.
• The developed method achieved high sensitivity, measuring amounts as low as approximately picomoles per square centimeter (pmol/cm(2)).
• The technique specifically detects amino groups exposed and available for surface functionalization.

Conclusions:

• A robust and sensitive method for quantifying surface amino groups using cleavable fluorescent probes has been established.
• Cleavable coumarin is a highly effective reagent for amino group quantification on silica and resin.
• This method provides valuable insights into surface properties relevant for biomolecule conjugation and advanced material design.