title: DNAzyme-functionalized Pt nanoparticles/carbon nanotubes for amplified sandwich electrochemical DNA analysis.
abstract: A novel DNAzyme-functionalized Pt nanoparticles/carbon nanotubes (DNAzyme/Pt NPs/CNTs) bioconjugate was fabricated as trace tag for ultrasensitive sandwich DNA detection. The Pt NPs/CNTs were prepared via layer-by-layer (LBL) assembly of the Pt NPs and polyelectrolyte on the carboxylated CNTs, followed by the functionalization with the DNAzyme and reporter probe DNA through the platinum-sulfur bonding. The subsequent sandwich-type DNA specific reaction would confine numerous DNAzyme/Pt NPs/CNTs bioconjugate onto the gold electrode surface for amplifying the signal. In the presence of 3,3',5,5' tetramethylbenzidine (TMB) which could be oxidized by the DNAzyme, electrochemical signals could be generated by chronoamperometry via the interrogation of reduction electrochemical signal of oxidized TMB. The constructed DNA sensor exhibited a wide linear response to target DNA ranging from 1.0 fM to 10 pM with the detection limit down to 0.6 fM and exhibited excellent selectivity against even a single base mismatch. In addition, this novel DNA sensor showed fairly good reproducibility, stability, and reusability.
authors: State Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors: Xiao-Ya
authors: XY
authors: Dong
authors: Xiao-Na
authors: XN
authors: Mi
authors: Long
authors: L
authors: Zhang
authors: Tong-Ming
authors: TM
authors: Liang
authors: Jing-Juan
authors: JJ
authors: Xu
authors: Hong-Yuan
authors: HY
authors: Chen
mesh_terms: D001483:Base Sequence; D001560:Benzidines / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000378:metabolism; D021881:DNA, Catalytic / Q000737:chemistry / Q000378:metabolism*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*
chemical_list: D001560:Benzidines; D021881:DNA, Catalytic; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; C021758:3,3',5,5'-tetramethylbenzidine; D010984:Platinum; D006046:Gold; D004247:DNA