A novel ratio colorimetric sensor based on magnetic nanoparticles(Fe3O4@Au)and silver nanoparticles(Ag NPs)was constructed for the detection of Ochratoxin A(OTA)by complementary DNA base pairing.The OTA aptamer coupled Fe3O4@Au was served as reference signal,and complementary DNA(cDNA)coupled Ag NPs was served as the response signal.A ratio nanoprobe(Fe3O4@Au-Ag)with two UV absorption peaks was prepared by regulating the ratio and DNA base complementarity.In absence of OTA,the absorbance peak ratio(A400/A580)of the ratio colorimetric sensor could maintain a constant value.The detection conditions(time,pH,and temperature)were optimized,and under optimized conditions,the sensor showed a good linear relationship to OTA detection,with a linear range of 0.01 ng·mL-1 to 1000 ng· mL-1 and a detection limit of 0.033 ng·mL-1.The sensor had good selectivity,reproducibility and high sensitivity,which was successfully applied to the detection of OTA in pea powder with a recovery rate of 93.9％～96.0％.
关键词
磁性纳米粒子/适配体/比率/比色传感器/赭曲霉毒素A
Key words
magnetic nanoparticle/aptamer/ratio/colorimetric sensor/ochratoxin A
维普
万方数据