A simple quinoxaline-based highly sensitive colorimetric and ratiometric sensor, selective for nickel and effective in very high dilution

Abstract A new quinoxaline based receptor ( HQNM) has been designed and synthesized which shows a remarkable color change from colorless to yellow on specific binding with nickel. The cation recognition property of the receptor is monitored by the UV–vis and 1 H NMR titrations. It is observed that the receptor shows a specific selectivity toward nickel over other interfering cations. Thus, a significant bathochromic shift in UV–vis spectrum with a sharp yellow color in ‘naked-eye’ makes the receptor suitable for the easy detection of nickel ion.