Ratiometric Luminescence Detection of Copper(I) by a Resonant System Comprising Two Antenna/Lanthanide Pairs

Selective and sensitive detection of Cu(I) is an ongoing challenge due to its important role in biological systems, for example. Herein, we describe a photoluminescent molecular chemosensor integrating two lanthanide ions (Tb3+ and Eu3+) and respective tryptophan and naphthalene antennas onto a polypeptide backbone. The latter was structurally inspired from copper-regulating biomacromolecules in Gram-negative bacteria and was found to bind Cu+ effectively under pseudobiological conditions (log K-cu(+) = 9.7 +/- 0.2). Ion regulated modulation of lanthanide luminescence in terms of intensity and long, millisecond lifetime offers perspectives in terms of ratiometric and time-gated detection of Cut. The role of the bound ion in determining the photophysical properties is discussed with the aid of additional model compounds.

Automated summary

This study presents a photoluminescent molecular chemosensor integrating lanthanide ions, tryptophan, and naphthalene antennas onto a polypeptide backbone for selective and sensitive detection of Cu(I) under pseudobiological conditions. The ion regulated modulation of lanthanide luminescence offers potential for ratiometric and time-gated detection of Cu(I), and the role of the bound ion in determining the photophysical properties is discussed with the aid of additional model compounds.