The electrochemical behavior of baicalein (BAI) was investigated at a glass carbon electrode (GCE) and a poly-L-lysine modified glass carbon electrode (PLL/GCE). The result showed that a pair of reversible redox peaks that did not emerge at GCE was observed at PLL/GCE, which indicated that PLL/GCE performed effective electrochemical response to BAI. Under optimal conditions, a good linear relationship between the anodic peak current and concentration was obtained in the range of 5.0×10－7～1.0×10－5 mol/L with the detection limit of 4.8×10－8 mol/L (S/N＝3). The responses of repeated measurements at the renewed surface of the PLL/GCE were examined with relative standard deviation of 4.3% (n＝10), respectively, indicating that the chemically modified electrode showed excellent reproducibility. The proposed method has been used to determine baicalein concentration in urine samples with satisfactory results.

Key words: electrochemistry, baicalein, poly-L-lysine