Boronate Affinity Fluorescent Nanoparticles for Förster Resonance Energy Transfer Inhibition Assay of cis-Diol Biomolecules.

Förster resonance energy transfer (FRET) has been essential for many applications, in which an appropriate donor-acceptor pair is the key. Traditional dye-to-dye combinations remain the working horses but are rather nonspecifically susceptive to environmental factors (such as ionic strength, pH, oxygen, etc.). Besides, to obtain desired selectivity, functionalization of the donor or acceptor is essential but usually tedious. Herein, we present fluorescent poly(m-aminophenylboronic acid) nanoparticles (poly(mAPBA) NPs) synthesized via a simple procedure and demonstrate a FRET scheme with suppressed environmental effects for the selective sensing of cis-diol biomolecules. The NPs exhibited stable fluorescence properties, resistance to environmental factors, and a Förster distance comparable size, making them ideal donor for FRET applications. By using poly(mAPBA) NPs and adenosine 5'-monophosphate modified graphene oxide (AMP-GO) as a donor and an acceptor, respectively, an environmental effects-suppressed boronate affinity-mediated FRET system was established. The fluorescence of poly(mAPBA) NPs was quenched by AMP-GO while it was restored when a competing cis-diol compounds was present. The FRET system exhibited excellent selectivity and improved sensitivity toward cis-diol compounds. Quantitative inhibition assay of glucose in human serum was demonstrated. As many cis-diol compounds such as sugars and glycoproteins are biologically and clinically significant, the FRET scheme presented herein could find more promising applications.