Recently I'm working on a group of nanoparticles as a special fluorescence probe, it's working well and shows a good linear range with one of the species of metal ions, but besides that it shows a non-linear response to another metal ion, too.
Can probes like this, according to linear range answering to desired ion and the non-linear range answering for another ion (Interfering ion), be introduced as "Selective Fluorescence Detectors" for desired ions or not?
Hi Ramin,
In a nutshell, whether a fluorescent indicator is "selective" depends on the application. Suppose the indicator responds to binding certain cations by some change in its fluorescence, and responds to 10E-10 molar free/labile/mobile Zn2+, but also binds Ca2+ with a Kd of 10E-4 molar. The indicator measurement of zinc ion will be interfered with by calcium binding in sea water because the free calcium concentration there is 10 mM, but not in most cells because the free calcium concentration therein is typically lower than the Kd for calcium, and little will be bound. Note that the calcium interferes even if it doesn't cause the fluorescence to change, because it occupies the binding site. The best way to express the selectivity of indicators of this type is to determine their Kd's for binding likely interferents.
Hi Ramin,
In a nutshell, whether a fluorescent indicator is "selective" depends on the application. Suppose the indicator responds to binding certain cations by some change in its fluorescence, and responds to 10E-10 molar free/labile/mobile Zn2+, but also binds Ca2+ with a Kd of 10E-4 molar. The indicator measurement of zinc ion will be interfered with by calcium binding in sea water because the free calcium concentration there is 10 mM, but not in most cells because the free calcium concentration therein is typically lower than the Kd for calcium, and little will be bound. Note that the calcium interferes even if it doesn't cause the fluorescence to change, because it occupies the binding site. The best way to express the selectivity of indicators of this type is to determine their Kd's for binding likely interferents.
Dr.Ghosh, probe worked well and linear, problem was a interfering ion which answered and react by our probe in some special situations...
Thanks Dr.Thompson for your answer, it was really helpful.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles