基于适配体-MOF模拟酶比色检测bPAG9OA北大核心CSTPCD

The aim of this study is to establish a new colorimetric method for the detection of bovine pregnancy associated glycoprotein 9(bPAG9)based on the metal-organic framework Fe-MIL-101 and double aptamer sandwich principle.In a typical experimental procedure,biotinylated aptamer1 was immobilized onto microplate to act as capture probes.Fe-MIL-101 functionalized aptamer 2 act as a signal probe.In the presence of bPAG9,aptamer 1 and aptamer 2 bind with bPAG9 and forma double aptamer sandwich structure on solid phase carrier.Fe-MIL-101 coupled to aptamer 2 enable to catalyze the colorless peroxidase substrate to yield a colorimetric output signal.Thus,the qualita-tive and quantitative analysis of bPAG9 could be realized by the change of colorimetric signal.The re-sults showed that under the optimal conditions,the linear detection range were 0.5-50 ng/mL for bPAG9 in buffered solution,with a limit of detection(LOD)of 0.13 ng/mL.The average recoveries of bPAG9 in blank serum samples were in the range of 89.4%-104%,and the relative standard devia-tions were less than 10%.Subsequently,the serum samples from Holstein cows at 28 days after in-semination were analyzed by the developed assay.The test results were confirmed with ultrasonogra-phy and compared with PAG-ELISA test kit.The diagnostic sensitivity,specificity,and accuracy of the developed assay were 92.5%,90.0%and 91.5%,respectively.The developed assay has such advantages as simple,noninvasive,and economical.It has a good application prospect in the field of cow early pregnancy detection.