All the chemicals and reagents employed in this work for synthetic purposes were from Sigma-Aldrich, and they were all used exactly as the supplier provided. Using a Milli-Q instrument from Millipore, water was purified. Sigma-Aldrich provided all of the analytical or HPLC grade solvents needed for the synthesis of fluorescent dyes or spectroscopic analysis. Supplements and media for cell culture acquired from Invitrogen.