I have a sample of mixtures containing polystyrene microspheres (PS-MS) with 3 different diameter sizes (bought from thermo), they all contain a green fluorescent dye inside the polymer matrix / inside the microspheres . I'm hoping to find a method to quantify the PS-MS of each size in the sample, what kind of method is most suitable in this case? Could doing a calibration curve using UV-Vis spectrophotometry achieve this? Or would all the sizes have absorption peaks at the same wavelength?
Are there any other better quantification methods that can be used in this case?
I could really use some advices, thank you.
Not so much significant. UV peaks all depend upon the absorption spectra of a particular molecule. One molecule will always have similar chemical nature irrespective of the length of chains.
Chapter Characterization of Polymer
It really depends on the nature of your sample and what size the micro spheres are, but as you are probably, aware having them all labeled with the same dye is not ideal. If your sample is well dispersed, you could consider flow cytometry, which works well with micro and large nanoparticles in my experience. You can sort particles passing the detector based on scattering and fluorescence intensity to get relative populations of each size but this doesn’t really work if you have a lot of aggregates.
Another technique you could use if you were working with fairly simple solutions would be a Nanosight Instrument if you have access to one and your particles were less than 3.5 micron.
And yeah trying to get particle size populations by UV Vis isn’t going to work out.
Possibly putting a drop on a microscope slide, taking an image and counting particle populations within an area analogous to cell counting is plausible at the micro scale.
Just getting differently labelled particles would simplify a lot though.
Dear Mr. Robinson peak wavelengths tend to be shifted toward the long wavelength region as the conjugated system gets larger.
Dear Oi Yan Michelle Chan I think that you can be using UV-Vis spectrophotometry to quantify the PS-MS according to the following two books.
https://link.springer.com/referenceworkentry/10.1007%2F978-3-642-36199-9_118-1
Chapter Characterization of Polymer
My Regards
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanoparticle Research