title: A novel electrochemical DNA biosensor based on HRP-mimicking hemin/G-quadruplex wrapped GOx nanocomposites as tag for detection of Escherichia coli O157:H7.
abstract: A novel sensitive electrochemical DNA biosensor was developed for amperometric detection of Escherichia coli O157:H7 (E. coli O157:H7). The graphene oxide (GOx) was utilized as nanocarrier to immobilize thionine (Thi) and the Au nanoparticles coated SiO2 nanocomposites (Au-SiO2) by electrostatic adsorption and the adsorption among nanomaterials. Then a large amounts of signal DNA (S2) and G-quadruplex were immobilized on the GOx-Thi-Au@SiO2 nanocomposites. Finally, hemin was intercalated into the G-quadruplex to obtain the hemin/G-quadruplex structure as HRP-mimicking DNAzyme. On the basis of the signal amplification strategy of GOx-Thi-Au@SiO2 nanocomposites and DNAzyme, the developed DNA biosensor could respond to 0.01 nM (S/N=3) with a linear calibration range from 0.02 to 50.0 nM E. coli O157:H7, which could be well accepted for early clinical detection. The studied system provides new opportunities, and might speed up disease diagnosis, treatment and prevention with pathogen.
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Deng
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
authors.forename: Lichao
authors.initials: L
authors.lastname: Fang
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
authors.forename: Kangkang
authors.initials: K
authors.lastname: Yu
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China. Electronic address: wenbinliangasu@gmail.com.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Liang
authors.affiliation: Department of Clinical Laboratory Science, College of Medical Laboratory, Southwest Hospital, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China. Electronic address: zhengalpha@yahoo.com.
authors.forename: Junsong
authors.initials: J
authors.lastname: Zheng
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D054856:G-Quadruplexes; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006427:Hemin / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D004269:DNA, Bacterial; D006427:Hemin; D006046:Gold; D006108:Graphite
keywords: DNA biosensor; DNAzyme; Escherichia coli O157:H7; G-quadruplex; Graphene oxide