Swiss team turns Egyptian Blue into nanosheets for real-time brain imaging

Researchers at Empa, ETH Zurich and Balgrist University Hospital rebuilt the ancient pigment Egyptian Blue into 2D nanosheets called Zurich Blue using industrial flame spray pyrolysis. With quantum yields up to 34% and emission at 1007 nm, the material tracked individual immune cells in the intact brains of living mice in real time.

• Quantum yield reaches 34%, up from 10.5% for bulk cuprorivaite in 2009
• Substituting barium, strontium and magnesium shifts emission from 910 to 1007 nm
• Imaging runs at more than 200 frames per second
• Flame spray pyrolysis is already used industrially to make titanium dioxide