Determination of bisphenol A in water by truncated aptamer-fluorescence method / 预防医学

ABSTRACT

Objective@#To establish a fluorescence method based on turncated aptamer for the determination of bisphenol A in water.@*Methods@#The bisphenol A truncated aptamer containing 38 bases was selected as a recognition module, and was modified with the fluorophore 6-FAM at the 5'end. The 3'end of the complementary sequence cDNA was modified with the quencher DABCYL. The standard solutions of bisphenol A and interfering compounds were configured. The detection system was established after optimizing the number of bases in cDNA, the concentration ratio of truncated aptamer to cDNA, the incubation temperature and time, and the pH of the buffer. The specificity and recovery experiments were carried out. @*Results@#When the complementary sequence cDNA included 9 bases, the concentration ratio of the truncated aptamer to cDNA was 11.5, the pH value of the buffer solution was 7.5, the cDNA was incubated at 55 ℃ for 60 minutes, in the concentration range of 10-75 pmol/L, the linear regression equation was y=2 230.7x+110 825, the correlation coefficient was 0.926. The limits of detection was 3.3 pmol/L. The difference values of fluorescence intensity between tetrabromobisphenol A, estradiol, estriol, bisphenol S and bisphenol A were obviously different, so there was no significant interference to the test result. The recovery rates were 97.8%, 98.8% and 102.3% with the spiked concentrations of 20.0, 40.0 and 60.0 pmol/L. The relative standard deviations were 4.4%, 2.1% and 2.6% (n=5), respectively. @*Conclusion@#The fluorescence method based on turncated aptamer has the advantages of easy operation, high sensitivity and specificity, which can be used for the determination of bisphenol A in water.