Dnamediated electrochemical reactions of fe4tmpypcl and. Isolated oxidation and reduction processes are not much good. Electrochemical readout is accomplished through the measurement of current generated from a catalytic cycle. Amperometric aptasensor for thrombin detection using enzyme mediated direct electrochemistry and dna based signal amplification strategy. Jan 30, 2011 dna mediated electrochemistry through 100mer monolayers revealed large signals for wellmatched duplexes, comparable to those observed with shorter duplexes. Dna was evaluated for each studied electrode see experimental. Although not detectable without dna, the redox potential of dnabound muty is. Distinct from conventional coppermediated click chemistry and ligasebased dna ligation, our approach is copper and enzymefree, making our method a simple and robust signal ampli. Sensitive, specific, and fast analysis of nucleic acids nas is strongly needed in medicine, environmental science, biodefence, and agriculture for the study of bacterial contamination of food and beverages and genetically modified organisms. Barton division of chemistry and chemical engineering, california institute of technology, pasadena, california 91125. Electrochemistry at dna modified surfaces provides an alternative approach to photochemistry or radiation biology for studying charge migration through the double helix. A dna electrochemistry platform has been developed to probe proteins bound to. Universal primers for the pcr mediated amplification of dna.
Electrocatalysis of ferricyanide reduction mediated by. Download pdf 4 mb abstract the aromatic core of double helical dna possesses the unique and remarkable ability to form a conduit for electrons to travel over exceptionally long molecular distances. Pdf universal primers for the pcrmediated amplification. These results support the application of dna modified hopg as a convenient and reproducible surface for electrochemical dna sensors using dna mediated charge transport.
Thus disulfide reduction in the dna backbone appears to be dnamediated. Dna duplexes are patterned onto the primary electrode array, while a secondary electrode array is used both to initiate dna monolayer formation and for electrochemical readout via dnamediated. Intraduplex dna mediated electrochemistry of covalently tethered redoxactive reporters. The base pair stack of dna has been demonstrated as a medium for longrange charge transport chemistry both in. Mediated nanotetrahedron enhances the clearance of senescent cells aihua qu key lab of synthetic and biological colloids, ministry of education, international joint research laboratory for biointerface and biodetection, state key lab of food science and technology, school of food science and technology, jiangnan. A process of this kind is known generally as an electrode process. In this cycle, dna mediated charge transport reduces an intercalative redox probe, methylene blue, to leucomethylene blue. Dna modified electrochemistry shows that the 4fe4s cluster of dna bound ding, an atpdependent helicase that repairs rloops, is redoxactive at cellular potentials and atp hydrolysis increases.
The base pair stack of dna has been demonstrated as a medium for longrange charge transport chemistry both in solution and at dna modified surfaces. Finally, this dna mediated reduction of mb occurs primarily via intra rather than inter duplex intercalation, as probed through varying the proximity and integrity of the neighboring duplex dna. Electrically monitoring dna repair by photolyase pnas. This form of the probe has a reduced affinity for dna, destacking from the helix and entering solution. Dna modified electrodes are extensively used in both the development of next generation diagnostic sensors 16 and the characterization of groundstate dna mediated electrochemistry 715. Dna mediated electrochemistry is found to be effective for the tempo probe linked with an acetylene linker but not for a saturated tempo connected through an ethylenediamine linker. Electrochemistry offers accurate, simple, inexpensive, and robust tools for the development of such analytical platforms that can successfully compete. Dna modified electrodes have been an essential tool for both gaining insights into the fundamental properties of dna and, due to the exquisite specificity of dna mediated charge.
Electrochemical studies of muty bound to a dnamodified gold electrode demonstrate that the 4fe4s cluster of muty can be accessed in a dnamediated redox reaction. Keywords electrochemical dna biosensors, hybridization, dnamediated electron transfer, electrochemical beacons, electrocatalytic sensors, redox indicators. Although not detectable without dna, the redox potential of dna bound muty is. Barton division of chemistry and chemical engineering, california institute of technology, pasadena, california 91125, usa abstract intraduplex dna mediated reduction is established as a general mechanism for the reduction of. Many different electrochemical reporters have been developed for dna modified electrodes, including. Initial solution experiments featured photoinduced dnamediated ct between welldefined donor and acceptor sites 8, 9.
A signalon electrochemical biosensor based on dnazyme. Electrochemistry at dnaderivatized electrodes provides a valuable methodology to examine dnabound redox reactions and may offer new insight into dnamediated electron transfers. The electrochemistry of these molecules is studied as a function of ionic strength to determine the necessity of tight binding to dna and the number of electrons involved in the redox reaction. The studies presented here once again highlight how sensitive dna mediated charge transport chemistry can be in reporting on dna structure. Oct 09, 20 intraduplex dna mediated reduction is established as a general mechanism for the reduction of distally bound stacked redoxactive species covalently tethered to dna through flexible alkane linkages. Coupling into the base pair stack is necessary for dna. Copperfree click chemistrymediated cyclic ligation. Thus disulfide reduction in the dna backbone appears to be dna mediated.
Dna electrochemistry and electrochemical sensors for. Spectral characterization reveals a weakening of the plasmon coupling due to dna. Electrochemical sensing of attomolar mirna combining cascade. Intraduplex dna mediated electrochemistry of covalently tethered redoxactive reporters catrina g. Left the bottom electrode modified with a dilute dna monolayer is responsible for generating electrochemical signals through dna mediated charge transport ct amplified by electrocatalysis.
Related snp via dnamediated growth of silver nanoparticles on single walled carbon nanotubes jia tao,a,c, peng zhao,b, jing zheng,b, cuichen wu,b muling shi,b jishan li,b yinhui lib and ronghua yang a,b, aschool of chemistry and biological engineering, changsha university of. Methylene blue mb, nile blue nb, and anthraquinone aq were covalently tethered to dna with three different covalent linkages. Numerous approaches to electrochemical detection have been developed, including direct electrochemistry of dna, electrochemistry at polymermodified electrodes, electrochemistry of dna specific redox reporters, electrochemical amplifications with nanoparticles, and electrochemical devices based on dna mediated charge transport chemistry. Affinitymediated homogeneous electrochemical aptasensor on a. Electrochemistry notes loudoun county public schools. Pdf electrochemical behavior of selfassembled dnagold. Dnamediated electrochemistry bioconjugate chemistry. Dna electrochemistry shows dnmt1 methyltransferase. Gorodetsky, omar green, eylon yavin, and jacqueline k. Electrochemical studies of muty bound to a dna modified gold electrode demonstrate that the 4fe4s cluster of muty can be accessed in a dna mediated redox reaction. Dna, electrochemistry at polymermodified electrodes, electrochemistry of dna specific redox reporters, electrochemical amplifications with nanoparticles, and electrochemical devices based on dna mediated charge transport chemistry. Dnabased electrochemical sensors exploit a range of different chemistries, but. Dnamediated electrochemistry bioconjugate chemistry the base pair stack of dna has been demonstrated as a medium for longrange charge transport chemistry both in solution and at dnamodified surfaces. The electrochemical behavior of ciprofloxacin cfx and its interaction with the.
Supporting information coupling into the base pair stack. To study the dna bound redox properties of enzymes with 4fe4s clusters, we used dna mediated electrochemistry, a robust method for directly measuring dna ct in the ground state 5, 31, 32 fig. One of the first studies to examine dna mediated charge transport utilized covalently bound metallointercalators to explore long range quenching of luminescence by dna mediated electron transfer. Dnamediated electrochemistry of disulfides on graphite. Amperometric aptasensor for thrombin detection using. It is examined via the use of electrochemical cells which are systems that incorporate a redox reaction to produce or utilize electrical energy. We found that p58c binds dna tightly and is coupled into the duplex for redox activity in the oxidized state but is more loosely associated with the dna and redoxinactive in the.
Handheld isothermal amplification and electrochemical. This property makes it popular to prepare dna based optical sensors. Dna binding compounds 1, 5, quantum dots, and metallization 15, 16. Dna binding shifts the redox potential of the transcription. Dna mediated electrochemistry through 100mer monolayers revealed large signals for wellmatched duplexes, comparable to those observed. Electrochemical studies of reaction of ciprofloxcin and dna. For analysis of targets with point mutation, after hybridization, due to the perturbation of the dna base stacking by the mismatched base pair, dna mediated charge transduction is interfered slinker et al. Even given this lower sensitivity toward dna, this current electrochemical method exhibits significantly lower levels of detection than obtainable by comparable uvvisiblebased methods 25, 28. Pdf electrochemical processes involving selfassembled nanoparticles are currently the. Multiplexed dnamediated electrochemistry caltechthesis. Her unwavering belief in my capabilities helped me to become the scientist i am today.
Barton division of chemistry and chemical engineering california institute of technology, pasadena, california 91125 to. Coupling into the base pair stack is necessary for dna mediated electrochemistry alon a. Dna mediated reduction is exceptionally sensitive to even subtle perturbations to the intervening. These data demonstrate that dna electrochemistry can be utilized to.
A onestep and labelfree, electrochemical dna detection using. Electrochemical sensing of attomolar mirna combining cascade strand displacement polymerization and reductant mediated amplification peng miao,ab abyiting jiang,ab atian zhang, yue huang,c and yuguo tang asuzhou institute of biomedical engineering and technology, chinese academy of sciences, suzhou 215163, p. Electrochemistry using selfassembled dna monolayers on. The redox couples found show a strong ph dependence consistent with formation of a disulfide radical anion or 2e reduction of the disulfide to the two thiols. Dnamediated electrochemical reactions of fe4tmpypcl. Dna mediated electrochemistry is found to be effective for the tempo probe linked. The electrochemistry of quinizarin revealed through its.
Earlier we used dna mediated electrochemistry to characterize perturbations in the intervening dna structures using a well stacked probe, but here how well the probe is itself stacked serves as a specific. Surpassing the detection limit and accuracy of the. It has been proposed that longrange electron transfer between distally boundproteins in a dna mediated reaction may play a role in damage. Dnamediated electrochemistry is found to be effective for the tempo probe linked with an acetylene linker but not for a saturated tempo connected through an ethylenediamine linker. Electrochemistry of dna monolayers modified with a. Electrochemistry at dna derivatized electrodes provides a valuable methodology to examine dna bound redox reactions and may offer new insight into dna mediated electron transfers. Dna electrochemistry thus provides a first assay to characterize the redox chemistry of dna binding, and, significantly, to begin to determine whether these proteins may utilize dna mediated redox chemistry within the cell. Dna modified gold electrodes have proven to be invaluable tools in both the study and the application of dna mediated charge transport ct chemistry 110. Intraduplex dna mediated reduction is established as a general mechanism for the reduction of distally bound stacked redoxactive species covalently tethered to dna through. Here, multiplexed dna modified electrodes are used to i gain new insights on the electrochemical coupling of metalloproteins to the dna. In this technique, an alkanethiolterminated, annealed duplex dna dsdna substrate is deposited on a. Without the support of my many mentors, colleagues, friends, and family this degree would not have been possible. This chemistry is exquisitely sensitive to structural perturbations in the base pair stack as occur with lesions, single base mismatches, and protein binding.
Dnamediated electrochemistry copyright permission to. A molecule associated with some monopartite begomoviruses. Pdf electrochemistrybased sensors offer sensitivity, selectivity and low cost. Thermal and electrochemical gate effects on dna conductance. A process of this kind can always be represented as a chemical reaction and is known generally as an electrode.
We developed a onestep and labelfree, electrochemical dna detection method using metal ionmediated molecular beacon mb probe specially designed to. Nov 04, 2008 here, we discuss the characteristic features, applications, and advantages of dna mediated electrochemistry. Electrochemical monitoring of dnamediated charge transport processes. Multiplexed electrochemistry of dnabound metalloproteins. To increase the sensitivity of mismatch detection and further improve discrimination, mb was coupled to freely diffusing fe cn 63 in an electrocatalytic cycle figure 5. Dna duplexes are patterned onto the primary electrode array, while a secondary electrode array is used both to initiate dna monolayer formation and for electrochemical readout via dna mediated.
In this work, taking this unique property of graphene in combination with the sensitive electrochemical transducer, we report a novel affinity mediated homogeneous electrochemical aptasensor using graphene modified glassy carbon electrode gce as the sensing platform. Dna mediated electrochemistry bioconjugate chemistry this chemistry is exquisitely sensitive to structural perturbations in the base pair stack as occur with lesions, single base mismatches, and protein binding. Both electrochemistry of dna interacting species and dna related electrocatalysis were shown to strongly depend on the dna surface coverage. In these systems, the supramolecular selfassembly of thiolmodified dna duplexes on a gold surface yields well defined monolayers that can serve as platforms for electrochemical assays of dna ct. In this work, a dual amplified signal enhancement approach based on coupling deoxyribozyme dnazymedriven bipedal dna walkers bdw and terminal deoxynucleotidyl transferase tdt mediated dna elongation signal amplifications has been developed for highly sensitive and labelfree electrochemical detection of thrombin in human serums. Electrochemistry of dna monolayers gorodetsky group. Electrochemistry is the study of the relationship between chemical change and electrical work. The inclusion of a single base mismatch in the dna duplex below the location of the disulfide leads to a significant attenuation in the electrochemical signal, while the inclusion of a mismatch above the disulfide has little effect on the electrochemistry observed. Duplex dna 1 m was incubated with the redox active species 5 m in phosphate buffer. Most importantly i would like to thank my advisor, jackie, who has been an amazing mentor and role model over the years. The presence of the nonzero peak current for the mediated oxygen reduction at high concentrations of dna is also likely a result of the qz adsorption. Citeseerx multiplexed dnamediated electrochemistry. While longrange ct was shown to yield oxidative damage in dna up to 200 a away from the bound oxidant 10, 11, dna ct.
Dna electrochemistry and electrochemical sensors for nucleic. The electrochemistry of these labels when incorporated into dna has been examined in dna films containing both well matched and mismatched dna. Thus the observed electrochemistry is dnamediated and a general characteristic of the dna, independent of the redox probe. For the aq probe, dnamediated electrochemistry is found with an acetylene linker to uridine but not with an alkyl chain to the 5 terminus of the oligonucleotide. Intraduplex dnamediated electrochemistry of covalently. Citeseerx document details isaac councill, lee giles, pradeep teregowda. The mechanism of electron transfer to the 4fe4s cluster in endoiii was next investigated on both loosely and closely packed dsdnamodified electrodes.