Intrinsically ESIPT-exhibiting and enhanced emission in polymer nanoparticles as signaling for sensing nitrite.

Affiliation

College of Chemistry and Food Engineering, Changsha University of Science and Technology, Changsha, 410114, PR China. Electronic address: [Email]

Abstract

A straightforward approach to the fabrication of intrinsically excited-state intramolecular proton transfer (ESIPT)-fluorescent polymer nanoparticles (e-PNPs) was developed. The e-PNPs were obtained by self-assembly of the homopolymers derived from 4-aminosalicylic acid in aqueous solution. By incorporating ESIPT modules into polymer nanoparticles, the ESIPT reaction can be endowed with moderate hydrophobic micro-environment by nanoparticle scaffolds, eliciting enhanced ESIPT emission. The newly developed e-PNPs exhibit strong tautomeric fluorescence(e-FL), good photostability, low-toxicity and favourable biocompatibility in aqueous solution. Upon the addition of NO2-, the e-FL can be significantly quenched owing to the reaction of NO2- with the amide groups on e-PNPs. From this basis, the fluorescence detection of NO2- was implemented, which showed a linear relationship between 0 nM and 110 nM with a detection limit of 2.3 nM. Furthermore, e-PNPs were used as nanoprobes to monitor the NO2- levels in HeLa cells by fluorescence imaging, demonstrating the ability of discrimination from different concentrations of NO2-. The proposed method can be applied to a wide range of other ESIPT modules to integrate into polymer nanoparticles and offer highly sensitive nanosensing platform for bioanalysis and molecular imaging.

Keywords

ESIPT-Exhibiting,NO(2)(-) sensing,Polymer nanoparticles,Tautomeric emission quenching,

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