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Updated: Aug 6, 2026
10:38
Synthesis and Calibration of Phosphorescent Nanoprobes for Oxygen Imaging in Biological Systems
Published on: March 3, 2010
Determination of Cellular Oxygen Consumption Rate Based on Phosphorescence Intensity Measurements Using a
Mari Seno1, Shuichi Shiozaki1, Toshitada Yoshihara1
1Department of Chemistry, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma376-8515, Japan.
Analytical Chemistry
|July 22, 2026
Summary
Researchers developed a novel blue-emitting probe using iridium (Ir) complexes to measure cellular oxygen consumption rate (OCR). This advancement allows for real-time monitoring of cellular metabolism and activity in cultured cells.
Area of Science:
- Biochemistry and Biophysics
- Materials Science
- Cell Biology
Background:
- Cellular oxygen (O2) consumption rate (OCR) is a key indicator of metabolic activity and energy production.
- Accurate and real-time measurement of OCR is crucial for understanding cellular processes.
- Existing methods may have limitations in sensitivity, real-time monitoring, or ease of use.
Purpose of the Study:
- To develop a novel blue-emitting extracellular O2 probe for estimating cellular oxygen consumption rate (OCR).
- To utilize iridium (Ir) complexes for sensitive and selective O2 detection in biological systems.
- To enable real-time OCR measurements in cultured cells using a microplate reader.
Main Methods:
- Synthesis of heteroleptic tris-cyclometalated Ir(III) complexes with modified 2-phenylpyridine ligands.
- Development of a blue-emitting probe (35CF3Irpic-PEG10000) by conjugating polyethylene glycol (PEG) to an Ir(III) complex.
- Characterization of the probe's photophysical properties, O2 sensitivity, biocompatibility, and photostability.
- Measurement of extracellular O2 concentration changes and calculation of OCR using Stern-Volmer kinetics.
Main Results:
- Identified 35CF3Irpic as a highly phosphorescent blue-emitting Ir(III) complex.
- 35CF3Irpic-PEG10000 demonstrated bright blue emission, high O2 sensitivity, good biocompatibility, and photostability.
- The probe enabled real-time tracking of extracellular O2 changes and accurate determination of cellular OCR.
- Simultaneous measurements confirmed the relationship between cellular activity, O2 status, and mitochondrial membrane potential.
Conclusions:
- A novel, highly efficient blue-emitting Ir(III) complex-based probe (35CF3Irpic-PEG10000) was successfully developed for extracellular O2 sensing.
- The probe facilitates precise, real-time measurement of cellular oxygen consumption rate (OCR) in cultured cells using standard microplate readers.
- This tool offers a valuable method for investigating cellular metabolism, activity, and the impact of various treatments on O2 dynamics.
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