“…Imidazole based juloidine chemoprobe showed selective sensing of different metal ions in different solvents Hornung et al, 2008) [13]. With the intent of developing new optical probes based on Schiff base ligand for selective sensing of metal ions, fluorescence turn-on probes have been described, wherein the mechanism of sensing has been largely attributed to internal charge transfer (ICT) (Karton-Lifshin et al, 2012;Delcamp et al, 2013;Goswami et al, 2013;Rihn et al, 2012) [14], chelation-enhanced fluorescence (CHEF) (Albers et al, 2006;Sreenath et al, 2011;Zhou et al, 2012;Tan et al, 2015) [15], photo-induced electron transfer (PET) (Liu et al, 2014;Baek et al, 2012;Masanta et al, 2011;Chen et al, 2015) [16] or fluorescent resonance energy transfer (FRET) Sapsford et al, 2006;Qin et al, 2015;Yuan et al, 2015) [17]. Among them, chelation-enhanced fluorescence probe is a current thrust in the active research field interesting.…”