Controlled synthesis of soluble conjugated polymeric nanoparticles for fluorescence detection

Abstract

Highly fluorescent soluble conjugated polymeric nanoparticles (SCPNs) were synthesized through Suzuki-type polycondensation in confined nanoreactors, resulted in well-controlled particle sizes and uniform particle-size distributions. The SCPNs showed a wide range of the fluorescence emission maximum from 380 nm to 525 nm. They were surface-functionalized with boronic acid groups, obtained the corresponding BA-SCPNs, and further applied to the detection of two physiologically important species glucose and Fe³⁺ based on their interactions with boronic acid groups. The fluorescence quenching efficiency reached up to 32.1% and 92.4% for glucose and Fe³⁺, respectively. Among these fluorescent probes, BA-SCPN 3 exhibited enhanced glucose sensitivity compared with fructose, which might own to the formation of 1 : 1 cyclic complexes with biboronic acid derivatives. Meanwhile, BA-SCPN 3 also showed superior Fe³⁺ selectivity compared with other metal ions probably due to the formation of metal hydroxides between Fe³⁺ and the abundant hydroxyl groups in the boronic acid.