A simple, highly selective ferrocene-based chalcone fluorescent probe for the detection of CrO42− and Cr2O72− ions

Abstract

Cr (VI) is the most common water contaminant and is used in aluminum plating, paint production, leather tanning, etc. Cr (VI) is a kind of inhaled and swallowed poison, can enter the body through the digestive tract, respiratory tract, skin mucous membranes, may occur after skin contact dermatitis, or allergic phenomenon, in view of the harm of Cr (VI) to the human body, the development of a probe that can detect two kinds of Cr (VI) in the environment is an urgent problem. In this paper, 1-ferrocenyl-3-(2-hydroxyphenyl) allyl ketone (Probe A) was synthesized by solid phase grinding using acetyl ferrocene and o-hydroxybenzaldehyde as raw materials and I₂ as catalyst by green synthesis method. It was found that 1-ferrocenyl-3-(2-hydroxyphenyl) allyl ketone had specific recognition ability to Cr₂O₇²⁻ and CrO₄²⁻ by UV spectroscopy and fluorescence spectroscopy. It has better anti-interference performance under complex conditions. In addition, it was found that the binding ratio, binding constant and detection limit of 1-ferrocenyl-3-(2-hydroxyphenyl) allyl ketone for Cr₂O₇²⁻ and CrO₄²⁻ were 1:1 and 3:2, respectively. 5.1330×10⁶ M⁻¹and 5.7048×10⁴ M⁻¹, 1.6714×10⁻⁴ M, 1.7246×10⁻⁴ M by UV titration experiment. The effect of pH and time on the recognition ions of 1-ferrocenyl-3-(2‑hydroxy-phenyl) allyl ketone was studied. In 80 min, the probe structure is stable, CrO₄²⁻ and Cr₂O₇²⁻ can be identified stably. when the pH of the solution is 7∼8, the identification effect of probe A on Cr₂O₇²⁻ and CrO₄²⁻ ions is the best. The sensing mechanism of 1-ferrocenyl-3-(2-hydroxyphenyl) allyl ketone with Cr₂O₇²⁻ and CrO₄²⁻ was obtained by infrared and nuclear magnetic titration. And we carried out the test strip experiment, observed that with the increase of concentration, the color of the test strip changes significantly, which can be used for "naked eye" identification, this method can be more convenient and rapid detection of Cr (VI) solution.