Construction of a novel flavonol fluorescent probe for copper (II) ion detection and its application in actual...

Copper is an essential trace element in the human body, and its level is directly related to many diseases. While the source of copper in human body is mainly intake from food, then the detection of copper ions (Cu²⁺) in food becomes crucial. Here, we synthesized a novel probe (E)-3-hydroxy-2-styryl-4H-benzo[h]chromen-4-one (NSHF) and explored the binding ability of NSHF for Cu²⁺ using nuclear magnetic resonance hydrogen spectroscopy (¹H NMR), high-resolution mass spectrometry (HRMS), Job's plot method and density functional theory (DFT). NSHF shows the advantages of fast response time, good selectivity and high sensitivity for Cu²⁺. The fluorescence intensity ratio (F/F₀) of NSHF shows a good linear relationship with the concentration of Cu²⁺ and the detection limit is 0.061 μM. NSHF was successfully applied to the detection of Cu²⁺ in real samples. In addition, a simple and convenient Cu²⁺ detection platform was constructed by combining NSHF with a smartphone and a UV lamp, which can realize the rapid detection of Cu²⁺. This work provides an effective tool for the real-time detection of Cu²⁺.