Sensitive and selective detection of glycine betaine using curcumin-based fluorescent molecule with real sample analysis

A highly selective biosensor for glycine betaine (GB) based on the curcumin derivative (1BHD) is described, which displays a significant visual change and a lower detection limit (76 nM). The GB sensor displays a 1:1 binding ratio and a binding constant of 9.042 × 10⁷ M⁻¹. The binding mechanism of 1BHD for glycine betaine was confirmed by ¹H NMR titration, mass spectrometry, and DFT calculation. The fluorescence intensity of 1BHD was selectively quenched by GB, and an obvious color change from yellow to orange was observed by the naked eye. The above results have been utilized to detect GB sensitively in blood and urine samples. Graphical Abstract: (Figure presented.)