title: An ultrasensitive label-free assay of 8-hydroxy-2'-deoxyguanosine based on the conformational switching of aptamer.
abstract: We developed a highly sensitive label-free assay of 8-hydroxy-2'-deoxyguanosine (8-OHdG) using 8-OHdG-aptamer (Apt) as the recognition element. The Apt was adsorbed onto the surface of gold nanoparticles (AuNPs), which prevents them from aggregating under high-salt conditions. Upon addition of 8-OHdG, the conformation of the Apt changes to form a G-quadruplex structure, which leads to the aggregation of the AuNPs along with the increase of the resonance light scattering intensity. The mechanism of 8-OHdG that induces Apt to form G-quadruplexes structure was studied by circular dichroism. The response signals linearly correlated with the concentration of 8-OHdG ranging from 90.8pM to 14.1nM with a detection limit of 27.3pM, which is much lower than that obtained by other methods. This method does not need any label steps and sophisticated equipment. The application for detection of 8-OHdG in real samples further demonstrated its reliability. This strategy would be helpful for developing a universal analytical method by simply replacing corresponding aptamers for various target molecules.
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China; College of Public Health, Dali University, Dali 671000, PR China.
authors.forename: Jia-Cheng
authors.initials: JC
authors.lastname: Wang
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China. Electronic address: yongsheng.w@tom.com.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Wang
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Xue
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Qiu-Mei
authors.initials: QM
authors.lastname: Qian
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Yong-Song
authors.initials: YS
authors.lastname: Wang
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Ji-Cheng
authors.initials: JC
authors.lastname: Yin
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Shan-Du
authors.initials: SD
authors.lastname: Liu
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D002942:Circular Dichroism / Q000379:methods*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008832:Microchemistry / Q000295:instrumentation; D009690:Nucleic Acid Conformation; D013194:Staining and Labeling
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: 8-hydroxy-2′-deoxyguanosine; Aptamer; Conformational switching; Gold nanoparticles; Resonance light scattering; Ultrasensitive assay