An Amidochlorin-Based Colorimetric Fluorescent Probe for Selective Cu2+ Detection

Abstract

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 (Cu2+) 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 Cu2+; and a fluorescence quenching was also determined. The research of fluorescent quenching of ACP-Cu2+ complexation showed the detection limit was 7.5 × 10−8 mol/L; which suggested that ACP can act as a high sensitive probe for Cu2+ and can be used to quantitatively detect low levels of Cu2+ in aqueous solution. In aqueous solution the probe exhibits excellent selectivity and sensitivity toward Cu2+ ions over other metal ions (M = Zn2+; Ni2+; Ba2+; Ag+; Co2+; Na+; K+; Mg2+; Cd2+; Pb2+; Mn2+; Fe3+; and Ca2+). The obvious change from pale yellow to blue upon the addition of Cu2+ could make it a suitable “naked eye” indicator for Cu2+.