Print this page Contact Sales

Oxygen-sensing Probes

The abundance of oxygen can have significant impacts on biological function; consequently, oxygen is an important biomarker. To make measurement of oxygen fast and efficient, Active Motif Chromeon offers a variety of fluorescent, oxygen-sensing ruthenium probes that have different solubilities in various organic or aqueous solvents. This makes it possible to choose a probe according to the requirements of your sample and assay type. The probes have decay times in the microsecond range (2-4 µs) and absorption and emission maxima of 455 nm and 613 nm, respectively. In addition, they are easy to handle, resistant to photobleaching and highly specific for oxygen.

Figure 1. Absorption and emission spectra of Ru(dpp)₃(PF₆)₂.

Quenching by Oxygen

The fluorescence of Ru(dpp)₃(PF₆)₂ is dynamically quenched by oxygen. Therefore, it can be used as a probe to measure oxygen by either intensity or decay time. To demonstrate, lifetime measurements were taken of increasing concentrations of oxygen. Results clearly show that the decay time of Ru(dpp)₃(PF₆)₂ has dropped by a factor of 2 at a partial O₂-pressure of 200 hPa due to dynamic quenching.

Figure 2: Stern-Volmer plot of the ratio of decay times in the absence and presence of the quencher O₂.

Advantages of Chromeon Oxygen-sensing Probes

• Measure O₂ based on luminescence intensity or decay time
• No photobleaching
• Easy handling of probes
• Highly selective for oxygen
• Choice of probes with different solubilities increases assay flexibility

Contents & Storage

All oxygen probes are supplied as a dry powder and are guaranteed stable for 6 months when stored at 4°C.