Acta Chimica Sinica ›› 2021, Vol. 79 ›› Issue (1): 87-92.DOI: 10.6023/A20080399 Previous Articles     Next Articles



任江波a, 王蕾b, 郭锐a, 唐永和a, 周红梅a, 林伟英a,c,*()   

  1. a 广西大学 光功能材料与化学生物学研究院 化学化工学院 南宁 530004
    b 南宁市食品药品检验所 南宁 530007
    c 济南大学 光功能材料与成像研究院 化学化工学院 材料科学与工程学院 济南 250022
  • 投稿日期:2020-08-31 发布日期:2020-10-17
  • 通讯作者: 林伟英
  • 作者简介:
    * E-mail: ; Tel.: +86-0771-3236493; Fax: +86-0771-3236493
  • 基金资助:
    国家自然科学基金(21672083); 国家自然科学基金(21877048); 国家自然科学基金(22077048); 广西大学启动基金(A3040051003)

A Naphthalimide-Based Fluorescent Probe for Detecting Intracellular pH and Its Biological Imaging Application

Jiangbo Rena, Lei Wangb, Rui Guoa, Yonghe Tanga, Hongmei Zhoua, Weiying Lina,c,*()   

  1. a Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
    b Nanning Institute for Food and Drug Control, Nanning 530007, China
    c Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, Jinan University, Jinan 250022, China
  • Received:2020-08-31 Published:2020-10-17
  • Contact: Weiying Lin
  • Supported by:
    the National Natural Science Foundation of China(21672083); the National Natural Science Foundation of China(21877048); the National Natural Science Foundation of China(22077048); the Startup Fund of Guangxi University(A3040051003)

The pH of lysosome in cells has significant affect to various biological activities, including autophagy, phagocytosis, enzyme processing and so on. The metastasis and apoptosis of cancer cells are closely related to change of the lysosomal pH. The nucleus is the largest organelle in eukaryotic cells which control the most important genetic and metabolic processes, and the enzymes involved in metabolic processes are sensitive to changes of pH. Therefore, it is very important to investigate the pH change in cells. Herein, we designed and synthesized a novel fluorescent probe NpH-1 via a simple two-step reaction. The probe uses naphthalimide as the fluorescent group and morpholine group as the pH responsive site, and regulates the fluorescence through the photoinduced electron transfer (PET) mechanism. The spectroscopic properties of NpH-1 response to pH changes were measured in the Britton-Robison buffers, whose buffering range was from 1.81 to 11.92. In the pH range from 3.0 to 10.0, NpH-1exhibited a very rapid and reversible response to pH change. The pKa of NpH-1 was 5.41. It showed a very high photostability. Moreover, the fluorescence emission of NpH-1 was not influenced by biological species including metal ions, anions and amino acids. NpH-1 showed very low cytotoxicity, which indicated that it could be applied for cell imaging. Thus, we monitored the pH changes in HeLa cells via stimulating them by Chloroquine. The cell imaging results showed that NpH-1 could be utilized for detection of pH changes in living cells. Furthermore, the colocalization experiments of the probe NpH-1 for various organelles including lysosome, mitochondria, Golgi, endoplasmic reticulum and cellular nucleus were carried out, and the results exhibited the probe NpH-1 mainly distributed in lysosome and nucleus, which implied that the probe could be applied for detection of pH change in complex intracellular environment.

Key words: Lysosome, Cell nucleus, pH, Fluorescent imaging, Naphthalimide