TY - JOUR
T1 - Design strategy for germanium-rhodamine based pH-activatable near-infrared fluorescence probes suitable for biological applications
AU - Koide, Yuichiro
AU - Kojima, Ryosuke
AU - Hanaoka, Kenjiro
AU - Numasawa, Koji
AU - Komatsu, Toru
AU - Nagano, Tetsuo
AU - Kobayashi, Hisataka
AU - Urano, Yasuteru
N1 - Funding Information:
We thank Dr. Tasuku Ueno and Dr. Mako Kamiya for their generous advice. This research was supported in part by a Grant-in-Aid for JSPS Fellows (to Y.K., R.K., and K.N.), by The Mochida Memorial Foundation for Medical and Pharmaceutical Research (grant to R.K.), and by a Grant-in-Aid for Scientific Research (KAKENHI) (Grant Nos. 23249004 and 26111012 to Y.U., Specially Promoted Research Grant Nos. 22000006 to T. N., and Grant Nos. 16H05099, 18H04609, and 19H05414 to K.H.) from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and SENTAN, JST to K.H.
Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Fluorescence probes that can detect pH are useful tools for biological research and clinical diagnosis. Here we report pH-activatable near-infrared fluorescence probes, based on hydroxymethyl germanium-rhodamine (HMGeR), that are suitable for a range of biological applications. The pKa, the ratio of the fluorescent form in an acidic environment, and the absorption/emission wavelengths can all be conveniently optimized. The most promising probe, 2-HM IGeR, offers significant advantages over currently available near-infrared pH probes, notably high quantum efficiency, appropriate pKa value for biological applications, and high photostability. Further, our molecular design strategy allows easy conjugation of the probes to biomolecules without loss of functionality. We illustrate the value of this strategy by developing probe-Herceptin® and probe-avidin conjugates to visualize pH change in cellular vesicles during endocytosis, and to visualize tumors in a mouse model, respectively. We believe 2-HM IGeR is currently among the best-in-class pH-activatable near-infrared probes for biological and medical research.
AB - Fluorescence probes that can detect pH are useful tools for biological research and clinical diagnosis. Here we report pH-activatable near-infrared fluorescence probes, based on hydroxymethyl germanium-rhodamine (HMGeR), that are suitable for a range of biological applications. The pKa, the ratio of the fluorescent form in an acidic environment, and the absorption/emission wavelengths can all be conveniently optimized. The most promising probe, 2-HM IGeR, offers significant advantages over currently available near-infrared pH probes, notably high quantum efficiency, appropriate pKa value for biological applications, and high photostability. Further, our molecular design strategy allows easy conjugation of the probes to biomolecules without loss of functionality. We illustrate the value of this strategy by developing probe-Herceptin® and probe-avidin conjugates to visualize pH change in cellular vesicles during endocytosis, and to visualize tumors in a mouse model, respectively. We believe 2-HM IGeR is currently among the best-in-class pH-activatable near-infrared probes for biological and medical research.
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U2 - 10.1038/s42004-019-0194-4
DO - 10.1038/s42004-019-0194-4
M3 - Article
AN - SCOPUS:85071170137
VL - 2
JO - Communications Chemistry
JF - Communications Chemistry
SN - 2399-3669
IS - 1
M1 - 94
ER -