title: Single-walled carbon nanotubes based quenching of free FAM-aptamer for selective determination of ochratoxin A.
abstract: Ochratoxin A, a toxin produced by Aspergillus ochraceus and Penicillium verrucosum, is one of the most abundant food-contaminating mycotoxins in the world. It has been classified by the International Agency for Research on Cancer (IARC) as a possible human carcinogen. In this paper, a sensitive and selective fluorescent aptasensor for ochratoxin A (OTA) detection was constructed, utilizing single-walled carbon nanotubes (SWNTs) as quencher which can quench the fluorescence of free unfolded toxin-specific aptamer attached with FAM (carboxyfluorescein). Without any coating materials as compared to graphene-oxide based sensor, we obtained the detection limit of our sensing platform based on SWNTs to be 24.1 nM with a linear detection range from 25 nM to 200 nM. This technique responded specifically to OTA without interference from other analogues (N-acetyl-L-phenylalanine, warfarin and OTB). It has also been verified for real sample application by testing 1% beer containing buffer solution spiked with a series of concentration of OTA.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Guo
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Ren
authors.forename: Jiahai
authors.initials: J
authors.lastname: Wang
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D052157:Aptamers, Nucleotide; D001483:Base Sequence; D005453:Fluorescence; D057230:Limit of Detection; D009183:Mycotoxins / Q000032:analysis*; D037742:Nanotubes, Carbon; D009793:Ochratoxins / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D009183:Mycotoxins; D037742:Nanotubes, Carbon; D009793:Ochratoxins; C025589:ochratoxin A