Application of Sensitive Sensor Modified with MWNTs/Al2O3/poly-L-lysine Composite for 17β –estradiol Determination in Pregnant Woman Blood

A novel disposable sensor modified with MWNTs/Al 2 O 3 /poly-L-lysine film was developed for detection of clinical 17β-estradiol (17β-E 2 ) urine samples in this study. The electrochemical behavior of 17β-E 2 was greatly increased due to the good electrocatalytic activity of MWNTs/Al 2 O 3 /poly-L-lysine nanocomposites. The optimum experimental conditions such as scan rate, pH, accumulation time were obtained, and the peak potentials of 17β-E2 was explored at about 530mV. The peak current of 17β-E 2 measured by CV displayed the good linear property with the increasing of the concentrations. Under optimized conditions, the disposable sensor displayed excellent analytical performance with linear ranges of 17β-E 2 from 0.5nM to 50nM. And a very low detection limit of 0.014 nM was attained. Furthermore, the MWNTs/Al 2 O 3 /poly-L-lysine SPE was used to the rapid and successful determination of the hormone in spiked synthetic and real clinical pregnant woman urine samples with wonderful selectivity and sensitivity.