TY - JOUR
T1 - Tuning the pKa of two-photon bis-chromophoric probes for ratiometric fluorescence imaging of acidic pH in lysosomes
AU - Zhang, Tongxin
AU - Xu, Di
AU - Poon, Chung Yan
AU - Wang, Xueli
AU - Bolze, Frédéric
AU - Li, Hung Wing
AU - Wong, Man Shing
N1 - Funding Information:
We are grateful for the financial support of GRF (HKBU 12301317)by the Research Grant Council of Hong Kong, the Faculty Research Grant of Hong Kong Baptist University (FRG2/17-18/057)and the National Natural Science Foundation of China (21675135). The PROCORE-France/Hong Kong Joint Research Scheme sponsored by the Consulate General of France in Hong Kong and the Research Grants Council of Hong Kong (F-HKBU203/17)was acknowledged for the travel grant support. This work was also financially supported by The Shandong Provincial Natural Science Foundation of China (ZR2017BB086). Ludovic Richert (Plateforme d'imagerie quantitative de la faculté de Pharmacie de l'Université de Strasbourg)is thanked for two-photon ratiometric imaging. We are grateful to Loic Deramo from Leica Microsystem for in cellulo two-photon excitation spectra on SP8 Dive. MIFOBIO thematic school from the CNRS GDR IMABIO is gratefully acknowledged to give a unique opportunity for advanced two-photon imaging.
Funding Information:
We are grateful for the financial support of GRF (HKBU 12301317 ) by the Research Grant Council of Hong Kong , the Faculty Research Grant of Hong Kong Baptist University ( FRG2/17-18/057 ) and the National Natural Science Foundation of China ( 21675135 ). The PROCORE-France/Hong Kong Joint Research Scheme sponsored by the Consulate General of France in Hong Kong and the Research Grants Council of Hong Kong ( F-HKBU203/17 ) was acknowledged for the travel grant support. This work was also financially supported by The Shandong Provincial Natural Science Foundation of China ( ZR2017BB086 ). Ludovic Richert (Plateforme d'imagerie quantitative de la faculté de Pharmacie de l’Université de Strasbourg) is thanked for two-photon ratiometric imaging. We are grateful to Loic Deramo from Leica Microsystem for in cellulo two-photon excitation spectra on SP8 Dive. MIFOBIO thematic school from the CNRS GDR IMABIO is gratefully acknowledged to give a unique opportunity for advanced two-photon imaging.
PY - 2019/9/1
Y1 - 2019/9/1
N2 - Lysosomes are organelles containing many hydrolytic enzymes responsible for degrading macromolecules. Abnormal lysosomal pH changes are known to associate with dysfunction of cells linking to various diseases such as cancer and neurodegenerative disorders. Thus, it is of paramount importance to monitor lysosomal pH changes in order to investigate the pathological conditions. We report herein two novel, highly sensitive and fast responsive bis-chromophoric ratiometric two-photon fluorescent probes with different emission wavelengths, namely VP and VL for acidic pH sensing in live cells. Importantly, by adopting bis-chromophoric approach, the VP and VL probes bearing pyridyl and quinolyl as acid sensing sites exhibit pKa values of 4.62 and 5.26, respectively, which are ideal for quantitative analysis of lysosomal pH changes in live cells. These two biocompatible probes are not only highly lysosomal targeting, sensitive towards pH change with distinct emission color shifting but also highly two-photon active in cells with excellent photostability and reversibility. These probes were successfully applied to ratiometrically track and image pH fluctuation in lysosomes of HeLa cells by one- and two-photon excited fluorescence microscopy. For the first time, we have demonstrated here that the bis-chromophoric strategy is a useful tool to effectively modify and tune the pKa of a fluorescent probe.
AB - Lysosomes are organelles containing many hydrolytic enzymes responsible for degrading macromolecules. Abnormal lysosomal pH changes are known to associate with dysfunction of cells linking to various diseases such as cancer and neurodegenerative disorders. Thus, it is of paramount importance to monitor lysosomal pH changes in order to investigate the pathological conditions. We report herein two novel, highly sensitive and fast responsive bis-chromophoric ratiometric two-photon fluorescent probes with different emission wavelengths, namely VP and VL for acidic pH sensing in live cells. Importantly, by adopting bis-chromophoric approach, the VP and VL probes bearing pyridyl and quinolyl as acid sensing sites exhibit pKa values of 4.62 and 5.26, respectively, which are ideal for quantitative analysis of lysosomal pH changes in live cells. These two biocompatible probes are not only highly lysosomal targeting, sensitive towards pH change with distinct emission color shifting but also highly two-photon active in cells with excellent photostability and reversibility. These probes were successfully applied to ratiometrically track and image pH fluctuation in lysosomes of HeLa cells by one- and two-photon excited fluorescence microscopy. For the first time, we have demonstrated here that the bis-chromophoric strategy is a useful tool to effectively modify and tune the pKa of a fluorescent probe.
KW - Bis-chromophore
KW - Lysosomal pH detection
KW - pH fluorescent probe
KW - Structure tuning
KW - Two-photon ratiometric imaging
UR - http://www.scopus.com/inward/record.url?scp=85064825381&partnerID=8YFLogxK
U2 - 10.1016/j.talanta.2019.04.042
DO - 10.1016/j.talanta.2019.04.042
M3 - Journal article
C2 - 31171192
AN - SCOPUS:85064825381
SN - 0039-9140
VL - 202
SP - 34
EP - 41
JO - Talanta
JF - Talanta
ER -
