title: Strand displacement activated peroxidase activity of hemin for fluorescent DNA sensing.
abstract: To efficiently regulate the catalytic activity of the peroxidase mimic hemin, this work designs a double-stranded DNA probe containing an intermolecular dimer of hemin, whose peroxidase activity can be activated by a DNA strand displacement reaction. The double-stranded probe is prepared by annealing two strands of hemin labelled DNA oligonucleotides. Using the fluorescent oxidation product of tyramine by H2O2 as a tracing molecule, the low peroxidase activity of the hemin dimer ensures a low fluorescence background. The strand displacement reaction of the target DNA dissociates the hemin dimer and thus significantly increases the catalytic activity of hemin to produce a large amount of dityramine for fluorescence signal readout. Based on the strand displacement regulated peroxidase activity, a simple and sensitive homogeneous fluorescent DNA sensing method is proposed. The detection can conveniently be carried out in a 96-well plate within 20 min with a detection limit of 0.18 nM. This method shows high specificity, which can effectively distinguish single-base mismatched DNA from perfectly matched target DNA. The DNA strand displacement regulated catalytic activity of hemin has promising application in the determination of various DNA analytes.
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China. hxju@nju.edu.cn.
authors: Quanbo
authors: Q
authors: Wang
authors: Nan
authors: N
authors: Xu
authors: Zhen
authors: Z
authors: Gui
authors: Jianping
authors: J
authors: Lei
authors: Huangxian
authors: H
authors: Ju
authors: Feng
authors: F
authors: Yan
mesh_terms: D001483:Base Sequence; D040761:Biomimetic Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D019281:Dimerization; D006427:Hemin / Q000737:chemistry*; D057230:Limit of Detection; D009195:Peroxidase / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D015342:DNA Probes; D006427:Hemin; D004247:DNA; D009195:Peroxidase