Ergot alkaloids are mycotoxins which can be found in food based on cereal-crops, due to a contamination of plants by fungi of the genus Claviceps. The ingestion of ergot contaminated cereal crops can lead to a severe ...Ergot alkaloids are mycotoxins which can be found in food based on cereal-crops, due to a contamination of plants by fungi of the genus Claviceps. The ingestion of ergot contaminated cereal crops can lead to a severe poisoning known as ergotism. For food and feed safety purposes, the extraction of ergot alkaloids from ergot contaminated flour was investigated. For the specific recognition of ergot alkaloids, DNA aptamer ligands specially selected for ergot alkaloids were grafted onto silica gel in order to construct a specific solid phase extraction system. The aptamer-functionalized silica gels were used to extract ergot alkaloids from a contaminated rye feed sample. The presence of ergot alkaloids eluted from the aptamer-functionalized silica gels was analyzed using LC-QTOF-MS. By using this simple system, it was possible to specifically extract ergosine, ergokryptine and ergocornine from an ergot contaminated rye feed sample. This aptamer-based extraction tool shows the applicability of aptamers for the specific extraction of toxins or natural compounds from turbid matrices in a one-step procedure.展开更多
In this study,a colorimetric biosensor was developed based on the use of aptamer-functionalized magnetic beads and catalytic hairpin assembly(CHA),in conjunction with a three-way junction DNA(3WJ/DNA)and isolated Gqua...In this study,a colorimetric biosensor was developed based on the use of aptamer-functionalized magnetic beads and catalytic hairpin assembly(CHA),in conjunction with a three-way junction DNA(3WJ/DNA)and isolated Gquadruplex/hemin DNAzyme triple signal amplification.This approach enabled the label-free,visual and sensitive detection of Escherichia coli O157:H7.The target bacterium binds to the aptamer,which releases complementary DNA,thereby triggering the CHA to produce 3WJ/DNA.The three ends of 3WJ/DNA can each form a G-quadruplex/DNAzyme,thereby catalyzing the 3,3′,5,5′-tetramethylbenzidine(TMB)-H2O2 system to turn blue.Notably,we provide a triple signal amplification method of G-quadruplex/hemin DNAzyme based on the triple end of CHA-3WJ/DNA by cleverly screening and designing an isolated G-quadruplex,significantly improving the sensitivity.The proposed method’s limit of detection(LOD)was 8 CFU/mL,exhibiting good linearity within the range of 10°-10^(8) CFU/mL.Impressively,the method successfully detected E.coli O157:H7 in ultrahightemperature-sterilized,pasteurized and raw milk,exhibiting good stability and reproducibility.展开更多
文摘Ergot alkaloids are mycotoxins which can be found in food based on cereal-crops, due to a contamination of plants by fungi of the genus Claviceps. The ingestion of ergot contaminated cereal crops can lead to a severe poisoning known as ergotism. For food and feed safety purposes, the extraction of ergot alkaloids from ergot contaminated flour was investigated. For the specific recognition of ergot alkaloids, DNA aptamer ligands specially selected for ergot alkaloids were grafted onto silica gel in order to construct a specific solid phase extraction system. The aptamer-functionalized silica gels were used to extract ergot alkaloids from a contaminated rye feed sample. The presence of ergot alkaloids eluted from the aptamer-functionalized silica gels was analyzed using LC-QTOF-MS. By using this simple system, it was possible to specifically extract ergosine, ergokryptine and ergocornine from an ergot contaminated rye feed sample. This aptamer-based extraction tool shows the applicability of aptamers for the specific extraction of toxins or natural compounds from turbid matrices in a one-step procedure.
基金supported by the Joint Funds of the National Natural Science Foundation of China[No.U21A20272].
文摘In this study,a colorimetric biosensor was developed based on the use of aptamer-functionalized magnetic beads and catalytic hairpin assembly(CHA),in conjunction with a three-way junction DNA(3WJ/DNA)and isolated Gquadruplex/hemin DNAzyme triple signal amplification.This approach enabled the label-free,visual and sensitive detection of Escherichia coli O157:H7.The target bacterium binds to the aptamer,which releases complementary DNA,thereby triggering the CHA to produce 3WJ/DNA.The three ends of 3WJ/DNA can each form a G-quadruplex/DNAzyme,thereby catalyzing the 3,3′,5,5′-tetramethylbenzidine(TMB)-H2O2 system to turn blue.Notably,we provide a triple signal amplification method of G-quadruplex/hemin DNAzyme based on the triple end of CHA-3WJ/DNA by cleverly screening and designing an isolated G-quadruplex,significantly improving the sensitivity.The proposed method’s limit of detection(LOD)was 8 CFU/mL,exhibiting good linearity within the range of 10°-10^(8) CFU/mL.Impressively,the method successfully detected E.coli O157:H7 in ultrahightemperature-sterilized,pasteurized and raw milk,exhibiting good stability and reproducibility.
