title: Cu(II)-coordinated GpG-duplex DNA as peroxidase mimetics and its application for label-free detection of Cu2+ ions.
abstract: Herein a facile method is proposed to construct DNA-based peroxidase mimetics simply assembled by polymorphic DNA and Cu(2+) ions. The Cu(II)-catalyzed oxidation of TMB in the presence of H2O2 can be significantly accelerated through Cu(II)-coordination with DNA scaffolds, of which a colorimetric change can be discerned by naked-eye. The reaction rates of DNA-Cu(II) complexes are directly associated with sequence composition as well as the secondary structure of DNA scaffold, e.g., the reaction rate decreases in the following order: GpG-duplex ≈ G-rich coil > G-quadruplex > C-rich coil > i-motif. It is the first report to explore a colorimetric Cu(2+) sensing system on the basis of peroxidase mimicking activities of polymorphic DNA-Cu(II) complexes. One of our most intriguing results is that the GpG-duplex DNA demonstrates the ability to sense Cu(2+) ions in aqueous solution without significant interference from other metal ions. The Cu(2+) detection limit of 1.2 nM is achieved with a linear response range of 1.2-100 nM, and the developed sensing system is potentially applicable for quantitative determination of Cu(2+) in drinking water samples.
authors.affiliation: Key Laboratory for Green Chemical Technology MOE, Key Laboratory of Systems Bioengineering MOE, Tianjin University, Tianjin 300072, People׳s Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Key Laboratory for Green Chemical Technology MOE, Key Laboratory of Systems Bioengineering MOE, Tianjin University, Tianjin 300072, People׳s Republic of China.
authors.forename: Xuyin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Key Laboratory for Green Chemical Technology MOE, Key Laboratory of Systems Bioengineering MOE, Tianjin University, Tianjin 300072, People׳s Republic of China.
authors.forename: Jinli
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Green Chemical Technology MOE, Key Laboratory of Systems Bioengineering MOE, Tianjin University, Tianjin 300072, People׳s Republic of China. Electronic address: fuyan@tju.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Fu
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation; D003124:Colorimetry / Q000295:instrumentation*; D003300:Copper / Q000032:analysis* / Q000737:chemistry*; D004247:DNA / Q000235:genetics*; D015226:Dinucleoside Phosphates / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009195:Peroxidase / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D015226:Dinucleoside Phosphates; C018309:guanylyl-(3'-5')-guanosine; D003300:Copper; D004247:DNA; D009195:Peroxidase
keywords: Biomimetics; Coordination; Copper; DNA; Peroxidase