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

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.

► A chemosensor for Cu(II) detection has been synthesized.
► It possesses both colorimetric and fluorescence responses towards Cu(II).
► High sensitivity and excellent selectivity have been achieved.
► Recognition process can be finished within less than 60 s.