| Abstract: | This article describes an up-conversion immunoassay (UCIA) method for the determination of diethylstilbestrol with homogenous and rapid properties. Biotinylated diethylstilbestrol was used as a bridge for the formation of a streptavidinated beads-biotin-diethylstilbestrol‐antibody-acceptor beads complex in the immunoassay. The complex gave out imitation fluorescence at a wavelength of 680 nm when its excitation wavelength was at 615 nm as a result of the generation of singlet oxygen. The optimal test conditions and analytical performance of the method were studied. The optimized reaction time of ≥ 80 min was determined. The best buffer of phosphate buffer containing the surfactant of Tween 20 was established. Additionally, the sound analysis result can be obtained with highest antibody concentration, which was set in the experiments. Calibration curve, fit by 4-parameters formulation, resulted in R2 values of 0.9989, a linear range from 0.025 to 12.5 ng/mL and the limit of detection (LOD) of 0.01 ng/mL. The results of trace diethylstilbestrol concentrations in water samples showed recoveries ranging from 92.0% to 95.0%, and coefficients of variation between 3–8%. The data suggest that UCIA method is a good method with sensitivity for the determination of diethylstilbestrol in water. |
