Efficient and selective singlet oxygen sensitized NIR luminescence of a neodymium(III) complex and its application in biological imaging

A responsive neodymium NIR emission (4F3/2→4I11/2, 9/2) was recorded upon binding with singlet oxygen (KB=1.79×106 M−1) via the anthracene moiety. The motif ytterbium analog served as a negative control with no significant NIR enhancement/quenching with the addition of the same amount of singlet oxygen. Our complex was also found to react with 1O2 generated by a known photosensitizer TMPyP inside HeLa cells without inducing cell death and display no significant cytotoxicity.