High-capacity 4-fluoro-2-formylphenylboronic acid functionalized silica nanoparticles for highly efficient enrichment of cis-diol-containing biomolecules

Abstract

Boronate affinity materials have attracted significant interest as efficient adsorbents for isolating and concentrating cis-diol-containing biomolecules. Traditional approaches using these materials typically require alkaline binding conditions (commonly requiring pH levels near 8.5), which present dual challenges of practical handling difficulties and potential structural instability of delicate compounds. Moreover, their limited molecular recognition capability restricts applications involving trace-level cis-diol substances, often making low-concentration extractions unfeasible. Addressing these limitations, we developed silica-based nanoparticles functionalized with 4-fluoro-2-formylphenylboronic acid (SiO₂@APTES@pFFPBA), representing the first implementation of pFFPBA in nanoparticle-based boronate affinity systems. This engineered nanomaterial demonstrates enhanced performance characteristics including operational capability under mildly acidic conditions (pH 6.0), superior molecular selectivity, increased adsorption efficiency, and exceptional aqueous stability. The SiO₂@APTES@pFFPBA composite exhibited strong affinity for cis-diol-bearing molecules, displaying dissociation constants (K_d) of 10⁻⁴ M and 10⁻⁶ M when interacting with adenosine and horseradish peroxidase (HRP), respectively. The material showed notable adsorption capacities of 45.87 ± 1.64 mg g⁻¹ and 86.54 ± 3.26 mg g⁻¹ for these two biomolecules. This capability allowed efficient isolation of trace-level cis-diol-containing biological substances in neutral or slightly acidic environments.