title: Detection of ochratoxin A (OTA) in coffee using chemiluminescence resonance energy transfer (CRET) aptasensor.
abstract: We report a chemiluminescence resonance energy transfer (CRET) aptasensor for the detection of ochratoxin A (OTA) in roasted coffee beans. The aptamer sequences used in this study are 5'-DNAzyme-Linker-OTA aptamer-3'-dabcyl. Dabcyl at the end of the OTA aptamer region plays as a quencher in CRET aptasensor. When hemin and OTA are added, the dabcyl-labeled OTA aptamer approaches to the G-quadruplex-hemin complex by formation of the G-quadruplex-OTA complex. The G-quadruplex-hemin complexes possess horseradish peroxidase (HRP)-like activity, and therefore, the HRP-mimicking DNAzyme (HRPzyme) catalyzes peroxidation in the presence of luminol and H2O2. Resonance energy transfer between luminol (donor) and dabcyl (acceptor) enables quenching of chemiluminescence signals. The signal decreases with increasing the concentration of OTA within the range of 0.1-100ngmL(-1) (limit of detection 0.22ngmL(-1)), and the level of recovery of the respective 1ngmL(-1) and 10ngmL(-1) spiked coffee samples was 71.5% and 93.3%. These results demonstrated the potential of the proposed method for OTA analysis in diverse foods.
authors.affiliation: Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Gwangju 61005, Republic of Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Jo
authors.affiliation: Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Gwangju 61005, Republic of Korea.
authors.forename: Hyoyoung
authors.initials: H
authors.lastname: Mun
authors.affiliation: World Institute of Kimchi, Gwangju 61755, Republic of Korea.
authors.forename: Su-Ji
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Agricultural Chemistry and Food Science & Technology, Gyeongsang National University, Jinju, Gyeongnam 52828, Republic of Korea.
authors.forename: Won-Bo
authors.initials: WB
authors.lastname: Shim
authors.affiliation: Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Gwangju 61005, Republic of Korea; Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Gwangju 61005, Republic of Korea. Electronic address: mkim@gist.ac.kr.
authors.forename: Min-Gon
authors.initials: MG
authors.lastname: Kim
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003069:Coffee / Q000737:chemistry*; D004735:Energy Transfer; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods*; D009793:Ochratoxins / Q000737:chemistry*
chemical_list: D003069:Coffee; D009793:Ochratoxins; C025589:ochratoxin A
keywords: Aptasensor; Chemiluminescence resonance energy transfer; Ochratoxin A; Quenching; Roasted coffee beans