Study on a colorimetric sensor with color switching: Naked-eye detection for Cu(II) ion

Abstract In this paper, we synthesize and report a Cu(II)-sensing probe of N′1,N′2-bis(4-(diethylamino)-2-hydroxybenzylidene)oxalohydrazide (BDHO) with two detection channels. Its colorimetric and fluorescence spectrophotometric responses towards Cu(II) ion are fully investigated. It is found that the absorption and emission spectra of BDHO are both sensitive towards Cu(II) ion with high sensitivity as well as excellent selectivity. In addition, the recognition of BDHO towards Cu(II) ion is also very quick and can be accomplished within less than 1 min. The actual sensing performance of BDHO towards Cu(II) ion is also tentatively explored.