Synthesis of the fluorescent polymer containing pyrene and its application in the detection of tea polyphenol

Abstract Tea polyphenol (TP) is used as a food additive to inhibit lipid peroxidation reactions and extend shelf life, but excessive intake can affect the human immune system. Therefore, developing effective TP detection is significant. Here, pyrene‐based polyimide (Py‐PI) was synthesized by one‐step condensation copolymerization. This polyimide possessed excellent solubility and photoluminescence due to the introduction of pyrene‐conjugated groups. It could be used as fluorescent probe for TP detection in solution. In addition, Py‐PI fluorescent test paper with different morphology were prepared by electrospinning. As the concentration of the spinning solution was 15 wt%, the bead‐like porous polymer electrospun membrane displayed excellent surface wettability which could make the water droplet completely penetrate into the sample within 6 min. The fluorescence enhancement phenomenon could be observed for 5 × 10 −6 mg/mL TP solution on Py‐PI test paper. Furthermore, interference investigation of pH on test paper indicated that the sample exhibited a relatively stable fluorescence “turn‐on” response in acidic conditions. This work provides a convenient and rapid detection of TP antioxidant in the future.