“…Small-molecule copper-ion sensors that produce optical signals are of great interest and we have identified 55 colorimetric and fluorescent copper sensors that have been reported in the literature in 2010. ,− Some designs that have been explored include chemosensors based on rhodamine ,,,,, and Schiff-base units. ,,,,,,,,,,, It is evident that while there have been many copper sensor designs, sensitivity and selectivity for naked-eye detection remain elusive. For example, of the 55 sensors mentioned above, only 14 sensors displayed naked-eye detection below 10 μM. ,,,,,,,,,,,,, Furthermore, only three of the studies challenged copper sensing in the presence of a competing metal ion ,, and none challenged copper sensing in the presence of 10-fold excess competing metal to copper, which is achieved in...…”