Fluorescein isothiocyanate-doped conjugated polymer nanoparticles for two-photon ratiometric fluorescent imaging of intracellular pH fluctuations.

Xiaohui Wang, Yuanxiangyi Feng, Jinhua Liu, Kun Cheng, Yuanan Liu, Wei Yang, Hongxin Zhang, Hongshang Peng

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 2022 Feb 15

filter terms:

Herein, we report a two-photon ratiometric fluorescent pH nanosensor based on conjugated polymer poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) nanoparticles loaded with pH-sensitive fluorescein isothiocyanate (FITC) for intracellular pH monitoring. The obtained nanosensor (FITC-PFO NPs) possesses high sensitivity, excellent stability, good reversibility, favorable two-photon excitability and low cytotoxicity. The ratiometric fluorescence of FITC and PFO (F517/F417) in FITC-PFO NPs solution shows an efficient pH-sensitive response over the pH range from 3 to 10 (pKa = 6.43) under two-photon excitation. Additionally, the FITC-PFO NPs is successfully applied for ratiometric imaging of intracellular pH and its fluctuation in both one-photon and two-photon excitation modes. Overall, the two-photon pH nanosensor based on FITC-PFO NPs exhibits great potential in crucial physiological and biological processes related to intracellular pH fluctuations. Copyright © 2021 Elsevier B.V. All rights reserved.

Citation

Xiaohui Wang, Yuanxiangyi Feng, Jinhua Liu, Kun Cheng, Yuanan Liu, Wei Yang, Hongxin Zhang, Hongshang Peng. Fluorescein isothiocyanate-doped conjugated polymer nanoparticles for two-photon ratiometric fluorescent imaging of intracellular pH fluctuations. Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy. 2022 Feb 15;267(Pt 1):120477