title: Tuning the Aggregation/Disaggregation Behavior of Graphene Quantum Dots by Structure-Switching Aptamer for High-Sensitivity Fluorescent Ochratoxin A Sensor.
abstract: The design of graphene quantum dots (GQDs)-aptamer bioconjugates as the new sensing platform is very important for developing high-sensitivity fluorescent biosensors; however, achieving new bioconjugates is still a great challenge. Herein, we report the development of a new high-sensitivity fluorescent aptasensor for the detection of ochratoxin A (OTA) based on tuning aggregation/disaggregation behavior of GQDs by structure-switching aptamers. The fluorescence sensing process for OTA detection involved two key steps: (1) cDNA-aptamer (cDNA, complementary to part of the OTA aptamer) hybridization induced the aggregation of GQD (fluorescence quenching) after cDNA was added into the GQDs-aptamer bioconjugate solution, and (2) the target of OTA triggered disaggregation of GQD aggregates (fluorescence recovery). Such new fluorescent sensing platform can be used to monitor OTA with a linear range of 0 to 1 ng/mL and very low detection limit of 13 pg/mL, which is among the best in all the developed fluorescent nanoparticles-based sensors. Such sensing strategy is also successful in analyzing OTA in practical red wine sample with 94.4-102.7% of recoveries and relative standard deviation in the range of 2.9-5.8%. The present works open a new way for signaling the target-aptamer binding event by tuning aggregation/disaggregation behavior of GQDs-bioconjugates.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering & Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education; College of Materials Science & Engineering, Beijing University of Chemical Technology , Beijing, 100029, China.
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering & Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education; College of Materials Science & Engineering, Beijing University of Chemical Technology , Beijing, 100029, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University , Changchun, 130012, China.
authors.forename: Guangsheng
authors.initials: G
authors.lastname: Pang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering & Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education; College of Materials Science & Engineering, Beijing University of Chemical Technology , Beijing, 100029, China.
authors.forename: Yingwei
authors.identifier: 0000-0001-8586-864X
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, China.|BIC-ESAT, College of Engineering, Peking University , Beijing 100871, China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Guo
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D009793:Ochratoxins / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014920:Wine / Q000032:analysis
chemical_list: D052157:Aptamers, Nucleotide; D009793:Ochratoxins; C000628730:graphene oxide; C025589:ochratoxin A; D006108:Graphite