title: Catalytic Hairpin Assembly-Programmed Porphyrin-DNA Complex as Photoelectrochemical Initiator for DNA Biosensing.
abstract: A catalytic hairpin assembly (CHA)-programmed porphyrin-DNA complex was designed to trigger the chemiluminescence as photoelectrochemical initiator for DNA sensing. First, the programmed double strand DNA (dsDNA) was formed using two hairpin DNAs as assembly components via target-assisted CHA reaction, and then immobilized on a capture DNA/CdS quantum dots modified electrode. The porphyrin (FeTMPyP) was conveniently assembled on a dsDNA scaffold via the groove interaction. The FeTMPyP@dsDNA complex possessed high catalytic activity toward luminol oxidation to generate the desirable chemiluminescence with high stability under various temperature and alkaline conditions. By integrating the signal amplification capacity of CHA and in situ FeTMPyP-mediated chemiluminescence as excitation light, an amplified photoelectrochemical sensing strategy is proposed for DNA detection. Under optimized conditions, the biosensor shows a wide linear range from 5 to 10000 fM with a detection limit of 2.2 fM. Moreover, the developed photoelectrochemical device exhibits excellent selectivity, high stability, and acceptable fabrication reproducibility. The CHA-programmed porphyrin-DNA strategy not only extends the applications of photoelectrochemistry, but also presents a novel methodology in bioanalysis.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zang
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Pinghua
authors.initials: P
authors.lastname: Ling
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D002384:Catalysis; D004247:DNA / Q000032:analysis* / Q000737:chemistry* / Q000235:genetics; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D055029:Inverted Repeat Sequences; D008027:Light; D057230:Limit of Detection; D008163:Luminescent Measurements; D008665:Metalloporphyrins / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010084:Oxidation-Reduction; D045663:Quantum Dots / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D013696:Temperature
chemical_list: C492721:5,10,15,20-tetrakis(N-methyl-4'-pyridyl)porphyrinato-iron(III); D019187:Cadmium Compounds; D008665:Metalloporphyrins; D013440:Sulfides; C034939:cadmium sulfide; D004247:DNA