•Copper chemistry in analyte-responsive fluorescent probes•Binding-based and reaction-based approaches for fluorescent turn-on probes•Fluorescent probes for labile copper, amino acids and small reactive speciesCopper chemistry has been capitalized on in a wide spectrum of biological events. The central importance of copper in biology lies in the diverse chemical reactivity of the redox-active transition metal ranging from electron transfer, small molecule binding and activation, to catalysis. In addition to its many different roles in natural biological systems, the diverse chemical reactivity of copper also represents a rich opportunity and resource to develop synthetic bioanalytical tools for the study of biologically important species and molecules. In this mini-review, fluorescent probes featuring a specific copper-based chemical reaction to selectively detect a biologically relevant analyte will be discussed. In particular, fluorescent probes for sensing labile copper ions, amino acids and small reactive species will be highlighted. The chemical principles, advantages and limitations of the different types of copper-mediated chemical reactions in these fluorescent probes will be emphasized.Download high-res image (267KB)Download full-size image

We report here a new bioinspired copper-based strategy of superoxide sensing and the development of sensitive (>90-fold fluorescence turn-on) and selective superoxide probes for imaging variations in the endogenous superoxide level in various live mammalian cells (HEK293T, HeLa and A431).

A water soluble [6]catenane consisting of two interlocking [3]catenanes was synthesised in 91% yield using readily accessible precursors. The new strategy features the simultaneous use of orthogonal Cu+–phenanthroline and CB[6]–ammonium interactions for preorganising the precursors and the efficient CB[6]-catalysed azide–alkyne cycloaddition as bond forming reactions for ring closing, resulting in high structural complexity and fidelity of the products without compromising interlocking efficiency. A related [4]catenane with three different types of macrocycles was also obtained in good yield.

A highly sensitive and selective nitroreductase probe, showing a rapid and strong bioluminescence enhancement (>100-fold in 5 minutes), and its initial application in the real time detection of both Gram positive and Gram negative live bacteria and monitoring of their growth has been reported.

A highly sensitive and selective nitroreductase probe, showing a rapid and strong bioluminescence enhancement (>100-fold in 5 minutes), and its initial application in the real time detection of both Gram positive and Gram negative live bacteria and monitoring of their growth has been reported.