A novel fluorescent probe based on 7,8-benzochromone-3-carbaldehyde-(rhodamine B carbonyl) hydrazone for detection of trivalent cations and Zn2+ in different systems

Abstract

Abstract In this article, a new fluorescence probe 7,8-benzochromone-3-carbaldehyde- (rhodamine B carbonyl) hydrazone (L) was synthesized, which had been explored to detect Zn2+ and trivalent metal ions M3+ (Al3+, Cr3+ and Fe3+). When the excitation wavelength was 490\u2009nm, L showed high selectivity and high sensitivity to M3+ which was superior to monovalent and divalent metal cations in methanol solution. In EtOH/H2O (15/1, V/V), L showed selective fluorescence response to Zn2+, when the excitation wavelength was set to 425\u2009nm. Furthermore, the detection limits of L for Fe3+, Al3+ and Cr3+ were 2.46\u2009×\u200910-9 M, 2.54\u2009×\u200910-9 M and 4.23\u2009×\u200910-8 M, respectively. And the detection limit of L for Zn2+ was calculated to be 1.45\u2009×\u200910-7 M. The coordination ratio between L and M3+ was determined from the Job’s plot (fluorescent spectrum) to be 2:1 and the coordination ratio of L and Zn2+ was 1:1. Additionally, L might be used as a colorimetric probe of Cu2+ in EtOH/H2O (15/1, V/V) solution., which could be observed with the naked eye from colorless to red in the presence of Cu2+.