Near-infrared fluorescent probes with BODIPY donors and rhodamine and merocyanine acceptors for ratiometric determination of lysosomal pH variance

Authors

Shuai Xia, Michigan Technological University
Mingxi Fang, Michigan Technological UniversityFollow
Jianbo Wang, Michigan Technological UniversityFollow
Jianheng Bi, Michigan Technological UniversityFollow
Wafa Mazi, Michigan Technological University
Yibin Zhang, Michigan Technological UniversityFollow
Rudy Luck, Michigan Technological UniversityFollow
Haiying Liu, Michigan Technological UniversityFollow

Document Type

Article

Publication Date

5-4-2019

Abstract

Three fluorescent probes have been developed by conjugating three different BODIPY donors to rhodamine and merocyanine acceptors for ratiometric determination of lysosomal pH variations. Probe A consists of a 1,3,5,7-tetramethyl-BODIPY donor and a near-infrared rhodamine acceptor bearing a lysosome-targeting morpholine residue. Probe B is composed of a 3,5-dimethyl-BODIPY donor and a near-infrared rhodamine acceptor modified with an o-phenylenediamine residue. Probe C contains a 3-styrene-functionalized BODIPY donor with longer wavelength emission and a near-infrared merocyanine acceptor containing a morpholine residue. Under neutral or basic pH conditions, the probes only show fluorescence from the BODIPY donors under BODIPY excitation because the rhodamine and merocyanine acceptors maintain closed spirolactam configurations. However, excitation at BODIPY absorption wavelengths concomitant with gradual pH decrease results in fluorescence decreases with the BODIPY donors and fluorescence increases from the rhodamine and merocyanine acceptors due to through-bond energy transfer from the donors to the acceptors. This is because the spirolactam ring opens under more acidic conditions and fluorescence of the acceptors results from significantly improved π-conjugation. These experimental results are substantiated with theoretical calculations on models of the different probes. The probes have all been used to determine lysosome pH variations in HeLa cells. Probe B was further utilized to successfully detect pH fluctuations in HeLa cells under oxidative stress induced with NH₄Cl and chloroquine.

Publisher's Statement

© 2019 Elsevier B.V. All rights reserved. Publisher's version of record: https://doi.org/10.1016/j.snb.2019.05.005

Publication Title

Sensors and Actuators B: Chemical

Recommended Citation

Xia, S., Fang, M., Wang, J., Bi, J., Mazi, W., Zhang, Y., Luck, R., & Liu, H. (2019). Near-infrared fluorescent probes with BODIPY donors and rhodamine and merocyanine acceptors for ratiometric determination of lysosomal pH variance. Sensors and Actuators B: Chemical, 294. http://doi.org/10.1016/j.snb.2019.05.005
Retrieved from: https://digitalcommons.mtu.edu/chemistry-fp/127