Efficient Detection of Environmental Estrogens Bisphenol A and Estradiol By Sensing System Based on AuNP-AuNP-UCNP Triple Structure / 分析化学

ABSTRACT

A sensing system based on AuNP-AuNP-UCNP triple structure for efficient detection of dual targets was constructed. In the preparation of triple structure, the gold nanoparticles (AuNPs) and upconversion nanoparticles (NaYF4 Yb, Er, Gd, UCNPs) were synthesized and surface modified. Then the two nanoparticles and their aptamers were connected to form two kinds of optical fluorescent probes. A nucleic acid sequence that matches with two aptamers was designed, rendering the probes to get close based on the principle of complementary base pairing. On the basis of this, a sensing system with a triple structure was prepared,and its connecting effect was characterized by TEM. With this system, dual targets of bisphenol A and estradiol were efficiently and conveniently detected through quantitative determination by fluorescence and UV spectrophotometer. At reaction temperature of 30℃ and pH=7.8,this method exhibited good linear range for determination of bisphenol A and estradiol from 2 ng/mL to 200 ng/mL and from 10 ng/mL to 150 ng/mL, with limits of detection of 0.2 ng/mL and 0.5 ng/mL, respectively. This sensing system with the triple structure owned better specificity to structural and functional analogues, and showed good repeatability and stability. What's more,this sensing system was applied in actual water detection,with the recoveries between 86.1% and 107. 4%, and the relative standard deviation below 6. 8%. This method showed promising applications in other environmental estrogens in water samples.