The first milestone of the SuperCol project has been achieved. The goal was to develop software to model the PSF of fluorophores on spherical nanoparticles. Teun Huijben and Kim Mortensen from DTU in Denmark have worked on this for the last year and now the software is ready to be shared with all other beneficiaries within the SuperCol consortium.
Teun and Kim developed an analytical description of the point-spread function for a dipole emitter near a spherical nanoparticle. The method is general, in the sense that the nanoparticle can have any size and material, and the dipole emitter can have any position and orientation with respect to the nanoparticle. Compared to popular numerical approaches, this analytical method is exact, 3 orders of magnitude faster, open-source, and does not require an expensive license to commercial numerical software packages.
This method, referred to as the PSF calculator, will allow for the reduction of mislocalizations by 1) serving as a predictive tool for optimal experimental design (e.g., nanoparticle material, size and fluorophore) and 2) as an exact PSF fitting algorithm. This method makes it possible to quickly (seconds instead of hours) and easily (open-source Python code) identify parameter regimes where the PSF is non-Gaussian or can be used in a fitting procedure to extract the true position of the fluorophore.
The analytical description is implemented in Python and is made available within the SuperCol consortium. After publication, the method will be shared publicly with everyone, stay tuned!