title: Design and fabrication of fluorescence resonance energy transfer-mediated fluorescent polymer nanoparticles for ratiometric sensing of lysosomal pH.
abstract: The design of effective tools capable of sensing lysosome pH is highly desirable for better understanding its biological functions in cellular behaviors and various diseases. Herein, a lysosome-targetable ratiometric fluorescent polymer nanoparticle pH sensor (RFPNS) was synthesized via incorporation of miniemulsion polymerization and surface modification technique. In this system, the donor: 4-ethoxy-9-allyl-1,8-naphthalimide (EANI) and the acceptor: fluorescein isothiocyanate (FITC) were covalently linked to the polymer nanoparticle to construct pH-responsive fluorescence resonance energy transfer (FRET) system. The FITC moieties on the surface of RFPNS underwent structural and spectral transformation as the presence of pH changes, resulting in ratiometric fluorescent sensing of pH. The as-prepared RFPNS displayed favorable water dispersibility, good pH-induced spectral reversibility and so on. Following the living cell uptake, the as-prepared RFPNS with good cell-membrane permeability can mainly stain in the lysosomes; and it can facilitate visualization of the intracellular lysosomal pH changes. This nanosensor platform offers a novel method for future development of ratiometric fluorescent probes for targeting other analytes, like ions, metabolites,and other biomolecules in biosamples.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China; Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, PR China. Electronic address: cj0066@gmail.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, PR China. Electronic address: pshzhang07@gmail.com.
authors.forename: Peisheng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, PR China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China. Electronic address: jianhuijiang@hnu.edu.cn.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Jiang
mesh_terms: D000498:Allyl Compounds / Q000737:chemistry*; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000378:metabolism* / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry*; D053644:Naphthalimides / Q000737:chemistry*; D061848:Optical Imaging / Q000379:methods; D010539:Permeability; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000498:Allyl Compounds; D005456:Fluorescent Dyes; D053644:Naphthalimides; D011108:Polymers; D014867:Water; D016650:Fluorescein-5-isothiocyanate
keywords: FRET; Lysosomal pH; Polymer nanoparticle; Ratiometric