Carborane- or Metallacarborane-Linked Nucleotides for Redox Labeling. Orthogonal Multipotential Coding of all Four DNA Bases for Electrochemical Analysis and Sequencing

Abstract

We report a series of 2′-deoxyribonucleoside triphosphates bearing dicarba-nido-undecaborategroups prepared either through the Sonogashira cross-coupling or the CuAAC click reaction. The modified dN X TPs were substrates for KOD XL DNA polymerase in enzymatic synthesis of modified DNA through primer extension (PEX). The nido-carborane-and FESAN-modified nucleotides gave analytically useful oxidation signals in square-wave voltammetry and were used for redox labeling of DNA. The redox-modified DNA probes were prepared by PEX using tailed primers and were hybridized to electrode (gold or glassy carbon) containing capture oligonucleotides. The combination of nido-carborane-and FESAN-linked nucleotides with 7-ferrocenylethynyl-7-deaza-dATP and 7-deaza-dGTP allowed polymerase synthesis of DNA fully modified at all four nucleobases, and each of the redox labels gave four differentiable and ratiometric signals in voltammetry. Thus, the combination of these four redox labels constitutes the first fully orthogonal redox coding of all four canonical nucleobases, which can be used for determination of nucleobase composition of short DNA stretches in one simple PEX experiment with electrochemical readout.

Electrochemistry of Cobalta Bis(dicarbollide) Ions Substituted at Carbon Atoms with Hydrophilic Alkylhydroxy and Carboxy Groups

“…The electronic structure in the inner orbital corresponds to a fully delocalized aromatic system [ 7 ], and along with the presence of a Co(III) central atom, generates interesting electrochemical properties [ 39 ]. Previous studies [ 24 , 39 , 40 , 41 , 42 , 43 ] and our recent results [ 44 ] suggest that the cobalta bis(dicarbollide) ion can be considered a good candidate for the tunable electrochemical labelling of biomolecules. Indeed, some icosahedral metallacarboranes have already been used as redox labels for the electrochemical detection of biomolecules [ 45 , 46 ].…”

“…Indeed, some icosahedral metallacarboranes have already been used as redox labels for the electrochemical detection of biomolecules [ 45 , 46 ]. The cobalta bis(dicarbollide) ion has been used in bioconjugation studies [ 3 , 4 , 40 , 41 ]. In addition, a study on the closely related ferra bis(dicarbollide) ion appeared recently in the literature [ 40 ].…”

Electrochemical Detection of Single-Nucleotide Polymorphism Associated with Rifampicin Resistance in Mycobacterium tuberculosis Using Solid-Phase Primer Elongation with Ferrocene-Linked Redox-Labeled Nucleotides

“…We have recently reported on the electrochemical detection of the ratiometric incorporation of four differentiable redox-labeled nucleotides, demonstrating their use in primer extension assays. 41 To use labeled dNTPs rather than ddNTPs, we explored the possibility of solid-phase primer elongation for the detection of SNPs. In this approach, first reported in 2001, primers containing a variable base (A, G, T, C) at their 3′ end were covalently immobilized via their 5′ ends to glass slides.…”

“…We were motivated to develop an alternative to fluorescence detection via the use of electrochemical detection, compatible with handheld potentiostats such as those used in glucometers, thus facilitating portability and cost-effectiveness. Exploiting our previous knowledge in the development of biosensors and in the use of redox-labeled nucleotides, 41 we wanted to combine this know-how to demonstrate a proof-of-concept for the cost-effective, rapid, and facile detection of SNPs in a platform that could easily be expanded to multiplexed detection with a plethora of niche applications.…”

Light‐Induced On/Off Switching of the Surfactant Character of the o‐Cobaltabis(dicarbollide) Anion with No Covalent Bond Alteration

“…[2] In the last decades, a vast number of studies have described its physical and chemical properties, highlighting its thermal and chemical stability, most probably due to its strong aromatic character. [2] These and other properties, in conjunction with its facile synthesis [3] and derivatization, [2] make this molecule highly attractive for the development of multiple applications in a plethora of fields, [4,5] including catalysis, [6,7] redox chemistry, [8] (bio)sensors, [9][10][11] medicine, [5,[12][13][14][15][16] metal-organic frameworks, [17] conducting polymers, [18,19] and surfactants, [20,21] among others. [5,22] Recently, Malaspina et al [20] rationalized the peculiar ability of [o-COSAN] À to form vesicles and micelles in bulk water, finding that the molecule has indeed very well differentiated hydrophobic and hydrophilic regions.…”