Quick and sensitive determination of cross conjugated flavonoids by tetramethylethylenediamine

Cross-conjugated flavonoids exhibited higher bioactivities in certain aspects compared to others. Applying them in food and medical industries could promote human health. Conjugated porous polymer (CPP) served as an excellent adsorbent for N,N,N′,N′-tetramethylethylenediamine (TEMED) due to its porous properties, large specific surface areas, and highly delocalized π−π conjugated skeleton. The constructed TEMED-CPP distinguished between flavonoids with or without cross conjugation. This method showed good linearity (R²≥0.979), low detection limits (0.19–1.84 μg/mL) and acceptable intraday and interday precision (≤9.97 %). Density functional theory and molecular planarity calculations indicated that degree of conjugation, planarity, and energy band gap of flavonoids collectively influenced their response sensitivity to TEMED-CPP. Additionally, CPP could be recycled and subsequently reloaded with TEMED for the next detection after its initial use. The rapid identification of cross-conjugated flavonoids could guide the extraction and enrichment processes of highly bioactive flavonoids from natural sources, which improved extraction efficiency and economic benefits.