NSM

<ul> <li> Source: [[ <a class="litnote tooltip" href="/literature/@spackova2022"> @spackova2022 <span class="tooltiptext"> Label-free nanofluidic scattering microscopy of size and mass of single diffusing molecules and nanoparticles </span> </a> ]] </li> <li> Tags: <a href="/tags/nanoparticle-sizing"> #nanoparticle-sizing </a> <a href="/tags/nanochannels"> #nanochannels </a> <a href="/tags/nanoparticle-tracking-analysis"> #nanoparticle-tracking-analysis </a> </li> </ul> <p> <img alt="nsm_schematic.jpeg" class="wikiimage" src="/nsm_schematic.jpeg"/> </p> <p> This paper displays an approach very similar to the one implemented by <a class="wikilink" href="/dispertech/"> Dispertech </a> , just that instead of using <a class="wikilink" href="/hollow_optical_fiber/"> hollow optical fiber </a> , they use a nano-fluidic chip with a rectangular cross section. The other difference is that they use a dark-field illumination approach, and instead of detecting the direct <a class="wikilink" href="/scattering_from_the_particle/"> scattering from the particle </a> , they measure in a mode similar to <a class="wikilink" href="/iscat/"> iSCAT </a> (see also: <a class="wikilink" href="/literature/202212091127_iscat_for_refractive_index_of_evs/"> 202212091127 iSCAT for refractive index of EVs </a> ). </p> <p> The principle of operation is that the nano-channel becomes a scatterer (sub-diffraction), and the particle inside creates an interference pattern that can be detected by a microscope. The signal is processed similarly to iSCAT, but in this case particles are moving in 1-D. </p> <p> Since the interference is happening at short scales (between the channel and the particle), I wonder if it is possible to use low-coherent sources, such as LED's instead of a laser (the paper uses a supercontinuum, delivering $\approx 200\,mW$ of power. ) </p> <p> <img alt="NSM_setup.jpeg" class="wikiimage" src="/nsm_setup.jpeg"/> </p> <p> The setup is a <a class="wikilink" href="/dark-field_microscope/"> dark-field microscope </a> (also see: <a class="wikilink" href="/literature/202310101212_stereo_darkfield_interferometry/"> 202310101212 Stereo Darkfield Interferometry </a> ) built on a Madcity Labs modular microscope (the micro-mirrors can move). </p> <p> I wonder why the choice of going for the "TIR" ( <a class="wikilink" href="/total_internal_reflection/"> total internal reflection </a> ) type of approach and not a classical dark-field with a stop in the center. </p> <p> Also, is it possible to replace the lens for a cylindrical lens to increase the intensity at the channel? </p> <p> The technology is commercialized by <a class="wikilink" href="/envue/"> Envue </a> . </p>