An Amidochlorin-Based Colorimetric Fluorescent Probe for Selective Cu(2+) Detection.

The design and synthesis of selective and sensitive chemosensors for the quantification of environmentally and biologically important ionic species has attracted widespread attention. Amidochlorin p6 (ACP); an effective colorimetric and fluorescent probe for copper ions (Cu(2+)) in aqueous solution derived from methyl pheophorbide-a (MPa) was designed and synthesized. A remarkable color change from pale yellow to blue was easily observed by the naked eye upon addition of Cu(2+); and a fluorescence quenching was also determined. The research of fluorescent quenching of ACP-Cu(2+) complexation showed the detection limit was 7.5 × 10(-8) mol/L; which suggested that ACP can act as a high sensitive probe for Cu(2+) and can be used to quantitatively detect low levels of Cu(2+) in aqueous solution. In aqueous solution the probe exhibits excellent selectivity and sensitivity toward Cu(2+) ions over other metal ions (M = Zn(2+); Ni(2+); Ba(2+); Ag⁺; Co(2+); Na⁺; K⁺; Mg(2+); Cd(2+); Pb(2+); Mn(2+); Fe(3+); and Ca(2+)). The obvious change from pale yellow to blue upon the addition of Cu(2+) could make it a suitable "naked eye" indicator for Cu(2+).