Singlet Oxygen Microscope: From Phase-Separated Polymers to Single Biological Cells

The lowest excited electronic state of molecular oxygen, singlet molecular oxygen (a1Δg), is an intermediate in many chemical and biological processes. Tools and methods have been developed to create singlet-oxygen-based optical images of heterogeneous samples that range from phase-separated polymers to biological cells. Such images provide unique insight into a variety of oxygen-dependent phenomena, including the photoinitiated death of cells.