Nanoparticle tag counting for tissue imaging using infrared laser ablation
|Year of publication
|MU Faculty or unit
|We report a new laser ablation technique employing a pulsed 2 940 nm laser and a simple ablation cell for digital mapping biomarkers in tissues using metal nanoparticle tags. Unlike the conventional laser ablation systems, where nanoparticles are ablated, we are able to desorb intact nanoparticles and count them. The method is demonstrated on monitoring proliferating cells in 3D aggregates of human colorectal carcinoma cells. Precise counting of the tags in each pixel generates sharp distribution maps of a proliferation biomarker in the tissue. A mass spectrometer detects up to 83% nanoparticles of a selected element with a single particle detection limit. Advantageously, the desorption of nanoparticles from regions outside the tissue is strongly suppressed.