(UV–vis) spectrophotometer measurements were performed using
a SpectraMax M5 multimode plate reader (Molecular Devices, San Jose,
CA). HPLC measurements were carried out using a 2690 Alliance HPLC
separation module coupled with a 2487 dual λ absorbance UV–vis
detector (Waters, Milford, MA). Analytes were weighed using a Mettler
Toledo XS104 analytical balance (Mettler-Toledo, Columbus, OH). Fluorescence
spectroscopy measurements were performed using a SpectraMax M5 multimode
plate reader (Molecular Devices, San Jose, CA).