A rhodamine and chromone based “turn-on” fluorescent probe (RC1) for Zn(II) in aqueous solutions and its application

[Display omitted] •A rhodamine and chromone based “turn-on” fluorescent probe (RC1) for Zn(II) 7-methoxychromone-3-carbaldehyde-(rhodamine B carbonyl) hydrazone was designed and synthesized.•High selectivity and sensitivity of RC1 towards Zn2+ over other metal ions were obtained.•Test strips containing the receptor molecule were easy of access and offered a practical, efficient and low-cost test kit for Zn2+ ions. In this paper, we constructed a novel turn-on fluorescent probe 7-methoxychromone-3-carbaldehyde-(rhodamine B carbonyl) hydrazone which contains rhodamine and chromone moieties (RC1) for the detection of Zn2+. This probe processes good selectivity and high sensitivity for Zn2+ in the presence of most other metal ions except Al(III), Cr(III), Cu(II) and Fe(III), and the fluorescence property of RC1 towards Zn2+ was hardly disturbed when the concentration of Al(III), Cr(III), Cu(II) or Fe(III) was lower than 5 μM. The photoinduced electron transfer process (PET) was proposed to explain the observed spectral responses. It could be seen that the probe RC1 formed complex with Zn2+ in 1:1 ratio based on Job’s plot analysis and mass spectrometry analysis. The detection limit of RC1 recognizing Zn2+ was low to 3.35 × 10−7 M. Furthermore, test strips containing the probe molecule (RC1) were easy of access and offered a practical, efficient and low-cost test tool for Zn2+.