Egyptian blue is one of the oldest artificial color pigments. It adorns the crown of the world-famous bust of Nefertiti. An international research staff headed by Dr. Sebastian Kruss from the Institute of Physical Chemistry on the University of Göttingen has built a new nanomaterial-based on the Egyptian blue pigment, which is ideally suited for applications in imaging utilizing near-infrared spectroscopy and microscopy.
Microscopy and optical imaging are essential instruments in primary research and biomedicine. They use compounds that can release light when ignited and called “fluorophores”. These substances are also used to stain very small structures in samples, enabling clear resolution utilizing modern microscopes. Most fluorophores shine in light seen to humans. When utilizing light in the near-infrared spectrum, with a wavelength beginning at 800 nanometres, a light goes even deeper into tissue and there are fewer distortions to the image. To date, however, there are just a few known fluorophores that work in the near-infrared spectrum.
The research staff has now succeeded in exfoliating extremely skinny layers from grains of calcium copper silicate, often referred to as Egyptian blue. These nanosheets are 100,000 times thinner than human hair and fluoresce within the close to infrared vary.