1.College of Food Science,Southwest University,Chongqing,China
Abstract:
A fluorometric patulin (PAT) assay is presented that is based on the use of magnetic reduced graphene oxide (rGO) and DNase I. The fluorescence of the PAT aptamer labelled with 6-carboxyfluorescein (FAM) is quenched by magnetized reduced graphene oxide (rGO-Fe3O4) due to fluorescence resonance energy transfer (FRET). However, in the presence of PAT, the labelled aptamer is stripped off from rGO-Fe3O4. The rGO-Fe3O4 is then magnetically separated so that the fluorescence of free labelled PAT aptamer is restored. DNase I cannot hydrolyze the aptamer on rGO-Fe3O4, but it can cleave the free aptamer-PAT complex. This will release FAM and PAT which can undergo a number of additional cycles to trigger the cleavage of abundant aptamer. Recycling of DNase I-assisted target therefore leads to a strong amplification of fluorescence and consequently to an assay with low limit of detection. The detection limit for PAT is as low as 0.28 μg L?1 which is about 13 times lower than that without using DNase I. The method offers a new approach towards rapid, sensitive and selective detection based on an aptamer. Conceivably, it has a wide scope in that it may be applied to numerous other analytes if appropriate aptamers are available.
Abstract Schematic of a fluorometric assay based on the use of magnetic graphene oxide and DNase I. It was applied to the determination of patulin. DNase I was introduced for recycling amplification. The detection limit is about 13 times lower than that without using DNase I. Figure a contains poor quality of text in image. Otherwise, please provide replacement figure file.Thank you. I will provide the figure file.
