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61.
Multiwalled Carbon Nanotubes‐Chitosan Modified Single‐Use Biosensors for Electrochemical Monitoring of Drug‐DNA Interactions 下载免费PDF全文
A multiwalled carbon nanotubes (CNT)‐chitosan (CHIT) modified pencil graphite electrode (CNT‐CHIT/PGE) was developed for the first time herein for electrochemical monitoring of the interaction of an anticancer drug, mitomycin C (MC) and DNA. The characterization of unmodified PGE, CHIT/PGE, CNT/PGE and CHIT‐CNT/PGE were performed by scanning electron microscopy and cyclic voltammetry techniques. The oxidation signals of MC and guanine were measured before and after interaction at the surface of CNT‐CHIT/PGEs using differential pulse voltammetry. Electrochemical impedance spectroscopy technique was also successfully utilized for monitoring of the interaction process at the surface of CNT‐CHIT/PGEs in different interaction times. 相似文献
62.
Programmable Engineering of a Biosensing Interface with Tetrahedral DNA Nanostructures for Ultrasensitive DNA Detection 下载免费PDF全文
Meihua Lin Jingjing Wang Guobao Zhou Jianbang Wang Na Wu Prof. Jianxin Lu Prof. Jimin Gao Prof. Xiaoqing Chen Dr. Jiye Shi Prof. Xiaolei Zuo Prof. Chunhai Fan 《Angewandte Chemie (International ed. in English)》2015,54(7):2151-2155
Self‐assembled DNA nanostructures with precise sizes allow a programmable “soft lithography” approach to engineer the interface of electrochemical DNA sensors. By using millimeter‐sized gold electrodes modified with several types of tetrahedral DNA nanostructures (TDNs) of different sizes, both the kinetics and thermodynamics of DNA hybridization were profoundly affected. Because each DNA probe is anchored on an individual TDN, its lateral spacing and interactions are finely tuned by the TDN size. By simply varying the size of the TDNs, the hybridization time was decreased and the hybridization efficiency was increased. More significantly, the detection limit for DNA detection was tuned over four orders of magnitude with differentially nanostructured electrodes, and achieved attomolar sensitivity with polymeric enzyme amplification. 相似文献
63.
Toward the Design of a Catalytic Metallodrug: Selective Cleavage of G‐Quadruplex Telomeric DNA by an Anticancer Copper–Acridine–ATCUN Complex 下载免费PDF全文
Zhen Yu Menglu Han Dr. James A. Cowan 《Angewandte Chemie (International ed. in English)》2015,54(6):1901-1905
Telomeric DNA represents a novel target for the development of anticancer drugs. By application of a catalytic metallodrug strategy, a copper–acridine–ATCUN complex (CuGGHK‐Acr) has been designed that targets G‐quadruplex telomeric DNA. Both fluorescence solution assays and gel sequencing demonstrate the CuGGHK‐Acr catalyst to selectively bind and cleave the G‐quadruplex telomere sequence. The cleavage pathway has been mapped by matrix assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) experiments. CuGGHK‐Acr promotes significant inhibition of cancer cell proliferation and shortening of telomere length. Both senescence and apoptosis are induced in the breast cancer cell line MCF7. 相似文献
64.
Indranil Sinha Dr. Célia Fonseca Guerra Prof. Dr. Jens Müller 《Angewandte Chemie (International ed. in English)》2015,54(12):3603-3606
The first parallel‐stranded DNA duplex with Hoogsteen base pairing that readily incorporates an Ag+ ion into an internal mispair to form a metal‐mediated base pair has been created. Towards this end, the highly stabilizing 6 FP ‐Ag+‐ 6 FP base pair comprising the artificial nucleobase 6‐furylpurine ( 6 FP ) was devised. A combination of temperature‐dependent UV spectroscopy, CD spectroscopy, and DFT calculations was used to confirm the formation of this base pair. The nucleobase 6 FP is capable of forming metal‐mediated base pairs both by the Watson–Crick edge (i.e. in regular antiparallel‐stranded DNA) and by the Hoogsteen edge (i.e. in parallel‐stranded DNA), depending on the oligonucleotide sequence and the experimental conditions. The 6 FP ‐Ag+‐ 6 FP base pair within parallel‐stranded DNA is the most strongly stabilizing Ag+‐mediated base pair reported to date for any type of nucleic acid, with an increase in melting temperature of almost 15 °C upon the binding of one Ag+ ion. 相似文献
65.
Discrimination Between 8‐Oxo‐2′‐Deoxyguanosine and 2′‐Deoxyguanosine in DNA by the Single Nucleotide Primer Extension Reaction with Adap Triphosphate 下载免费PDF全文
Dr. Yosuke Taniguchi Yoshiya Kikukawa Prof. Dr. Shigeki Sasaki 《Angewandte Chemie (International ed. in English)》2015,54(17):5147-5151
The adenosine derivative of 2‐oxo‐1,3‐diazaphenoxazine (Adap) exhibits a superb ability to recognize and form base pairs with 8‐oxo‐2′‐deoxyguanosine (8‐oxo‐dG) in duplex DNA. In this study, the triphosphate of Adap (dAdapTP) was synthesized and tested for single nucleotide incorporation into primer strands using the Klenow Fragment. The efficiency of dAdapTP incorporation into 8‐oxo‐dG‐containing templates was more than 36‐fold higher than with dG‐containing templates, and provides better discrimination than does the incorporation of natural 2′‐deoxyadenosine triphosphate (dATP). The selective incorporation of dAdapTP into 8‐oxo‐dG templates was therefore applied to the detection of 8‐oxo‐dG in human telomeric DNA sequences extracted from H2O2‐treated HeLa cells. The enzymatic incorporation of dAdapTP into 8‐oxo‐dG‐containing templates may provide a novel basis for sequencing oxidative DNA damage in the genome. 相似文献
66.
Lukas Stolzer Antonina Vigovskaya Prof. Christopher Barner‐Kowollik Dr. Ljiljana Fruk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(41):14309-14313
A photochemical approach based on nitrile imine‐mediated tetrazole‐ene cycloaddition is introduced to functionalize gold nanorods with biomolecules. For this purpose, a bifunctional, photoreactive linker containing thioctic acid as the Au anchoring group and a tetrazole moiety for the light‐induced reaction with maleimide‐capped DNA was prepared. The tetrazole‐based reaction on the nanoparticles’ surface results in a fluorescent pyrazoline product allowing for the spectroscopic monitoring of the reaction. This first example of nitrile imine‐mediated tetrazole‐ene cycloaddition (NITEC)‐mediated biofunctionalization of Au nanorods paves the way for the attachment of sensitive biomolecules, such as antibodies and other proteins, under mild conditions and expands the toolbox for the tailoring of nanomaterials. 相似文献
67.
Biofunctionalization of Polyoxometalates with DNA Primers,Their Use in the Polymerase Chain Reaction (PCR) and Electrochemical Detection of PCR Products 下载免费PDF全文
Dr. Ahmed M. Debela Dr. Mayreli Ortiz Dr. Valerio Beni Prof. Serge Thorimbert Dr. Denis Lesage Prof. Richard B. Cole Prof. Ciara K. O'Sullivan Prof. Bernold Hasenknopf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17721-17727
The bioconjugation of polyoxometalates (POMs), which are inorganic metal oxido clusters, to DNA strands to obtain functional labeled DNA primers and their potential use in electrochemical detection have been investigated. Activated monooxoacylated polyoxotungstates [SiW11O39{Sn(CH2)2CO}]8? and [P2W17O61{Sn(CH2)2CO}]6? have been used to link to a 5′‐NH2 terminated 21‐mer DNA forward primer through amide coupling. The functionalized primer was characterized by using a battery of techniques, including electrophoresis, mass spectrometry, as well as IR and Raman spectroscopy. The functionality of the POM‐labeled primers was demonstrated through hybridization with a surface‐immobilized probe. Finally, the labeled primers were successfully used in the polymerase chain reaction (PCR) and the PCR products were characterized by using electrophoresis. 相似文献
68.
Pau Turon Prof. Dr. Jordi Puiggalí Dr. Oscar Bertrán Prof. Dr. Carlos Alemán 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):18892-18898
Even in the worst of conditions, such as those which occurred during mass extinction events, life on Earth never totally stopped. Aggressive chemical and physical attacks able to sterilize or poison living organisms occurred repeatedly. Surprisingly, DNA was not degraded, denatured or modified to the point of losing the capability of transferring the genetic information to the next generations. After the events of mass extinction life was able to survive and thrive. DNA was passed on despite being an extremely fragile biomolecule. The potential implications of hydroxyapatite protection of DNA are discussed in this Concept article including how DNA acts as a template for hydroxyapatite (HAp) formation, how cell death can trigger biomineralization, and how DNA can be successfully released from HAp when the conditions are favorable for life. 相似文献
69.
Paula Miro Virginie Lhiaubet‐Vallet M. Luisa Marin Miguel A. Miranda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):17051-17056
A new mechanism of photosensitized formation of thymine (Thy) dimers is proposed, which involves generation of a delocalized triplet excited state as the key step. This is supported by chemical evidence obtained by combining one benzophenone and two Thy units with different degrees of freedom, whereby the photoreactivity is switched from a clean Paternò–Büchi reaction to a fully chemo‐, regio‐, and stereoselective [2+2] cycloaddition. 相似文献
70.
Substituting CF2 for O4′ in Components of Nucleic Acids: Towards Systems with Reduced Propensity to Form Abasic Lesions 下载免费PDF全文
Dr. Yevgen P. Yurenko Dr. Jan Novotný Prof. Dr. Vladimir Sklenář Prof. Dr. Radek Marek 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17933-17943
Intrinsic structural features and energetics of nucleotides containing variously fluorinated sugars as potential building blocks of DNA duplexes and quadruplexes are explored systematically using the modern methods of density functional theory (DFT) and quantum chemical topology (QCT). Our results suggest that fluorination at the 2′‐β or 2′‐α,β positions somewhat stabilizes in vacuo the AI relative to the BI conformations. In contrast, substitution of the CF2 group for the O4′ atom (O4′‐CF2 modification) leads to a preference of the BI relative to AI DNA‐like conformers. All the studied modifications result in a noticeable increase in the stability of the glycosidic bond [estimated by the relaxed force constants (RFC) approach], with particularly encouraging results for the O4′‐CF2 derivative. Consequently, the O4′‐CF2 modified systems are suggested and explored as promising scaffolds for the development of duplex and quadruplex structures with reduced propensity to form abasic lesions and to undergo DNA damage. 相似文献