Development of a Ratiometric Fluorescent Cu(II) Indicator Based on Poly(<i>N</i>-isopropylacrylamide) Thermal Phase Transition and an Aminopyridyl Cu(II) Ligand oleh Lea Nyiranshuti, Emily R. Andrews, Leonid I. Povolotskiy, Frances M. Gomez, Nathan R. Bartlett, Arun Timothy Royappa, Arnold L. Rheingold, William Rudolf Seitz, Roy P. Planalp