Oligonucleotide‐Based Luminescent Detection of Metal Ions

Ma, Dik‐Lung; Chan, Daniel Shiu‐Hin; Man, Bradley Yat‐Wah; Leung, Chung‐Hang

doi:10.1002/asia.201000870

Cited by 83 publications

(34 citation statements)

References 157 publications

(186 reference statements)

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“…For example, physical adsorption of aptamers on carbon-based materials resulted in numerous aptasensors, this simplifying the manufacturing procedures of many optical or electrochemical sensors [ 20 , 21 , 22 ]. Similarly, straightforward procedures for stable strong attachment of aptamers to nanomaterials allowed the development of sensitive and reusable aptasensors based on fluorescence [ 23 ], colorimetry [ 24 ], luminescence [ 25 ], quartz crystal microbalance (QCM) [ 26 ], interferometry [ 27 ], plasmon resonance [ 28 ] or localized surface plasmon resonance [ 29 ] and electrochemistry. The most common surface functionalizations include covalent, gold-thiol, or biotin-streptavidin attachments.…”

Section: Aptamersmentioning

confidence: 99%

Graphene and Other Nanomaterial-Based Electrochemical Aptasensors

Hernandez

Özalp

2012

Biosensors

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Electrochemical aptasensors, which are based on the specificity of aptamer-target recognition, with electrochemical transduction for analytical purposes have received particular attention due to their high sensitivity and selectivity, simple instrumentation, as well as low production cost. Aptamers are functional nucleic acids with specific and high affinity to their targets, similar to antibodies. However, they are completely selected in vitro in contrast to antibodies. Due to their stability, easy chemical modifications and proneness to nanostructured device construction, aptamer-based sensors have been incorporated in a variety of applications including electrochemical sensing devices. In recent years, the performance of aptasensors has been augmented by incorporating novel nanomaterials in the preparation of better electrochemical sensors. In this review, we summarize the recent trends in the use of nanomaterials for developing electrochemical aptasensors.

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Section: Aptamersmentioning

confidence: 99%

Graphene and Other Nanomaterial-Based Electrochemical Aptasensors

Hernandez

Özalp

2012

Biosensors

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“…It is intriguing that, more than three decades after its discovery, the exact mechanism of G4-DNAzyme is still unclear and debated [5][6][7][8]. Despite this, dozens of new G4-DNAzymes are reported yearly [9][10][11][12] with multiple biosensing applications [13,14] ranging from metal detection [15][16][17][18] to mRNA detection [19,20], now resolutely pointing towards industry-relevant applications. Over the past years, various strategies have been devised to improve the overall catalytic efficiency of G4-DNAzymes and make them competitive with hemoproteins.…”

Section: Introductionmentioning

confidence: 99%

Improved performances of catalytic G-quadruplexes (G4-DNAzymes) via the chemical modifications of the DNA backbone to provide G-quadruplexes with double 3′-external G-quartets

Virgilio

Esposito

Lejault³

et al. 2020

International Journal of Biological Macromolecules

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Here we report on the design of a new catalytic G-quadruplex-DNA system (G4-DNAzyme) based on the modification of the DNA scaffold to provide the DNA pre-catalyst with two identical 3'-ends, known to be more catalytically proficient than the 5'-ends. To this end, we introduced a 5'-5' inversion of polarity site in the middle of the G4-forming sequences AG 4 A and AG 6 A to obtain d(3' AGG 5'-5' GGA 3') (or AG 2-G 2 A) and d(3' AGGG 5'-5' GGGA 3') (or AG 3-G 3 A) that fold into stable G4 whose tetramolecular nature was confirmed via nuclear magnetic resonance (NMR) and circular dichroism (CD) investigations. Both AG 2-G 2 A and AG 3-G 3 A display two identical external G-quartets (3'-ends) known to interact with the cofactor hemin with a high efficiency, making the resulting complex competent to perform hemoprotein-like catalysis (G4-DNAzyme). A systematic comparison of the performances of modified and unmodified G4s lends credence to the relevance of the modification exploited here (5'-5' inversion of polarity site), which represents a new chemical opportunity to improve the overall activity of catalytic G4s.

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“…The folding and stability of G-quadruplexes are particularly sensitive to cations. [4b, 15] This property has led some groups to propose the use of quadruplexes as a metal detection platform, [16] "DNA logic gates", [17] and molecular switches for charge transport, [18] intramolecular energy transfer [19] or binding affinity. [20] Besides such materialsdriven applications, establishing the structure and stability of aptamers in the presence of different cations is essential from the biosensing perspective, since any change in the structure of the aptamer could influence its sensing capacity.…”

Section: Introductionmentioning

confidence: 99%

Elongated Thrombin Binding Aptamer: A G‐Quadruplex Cation‐Sensitive Conformational Switch

Rache

Kejnovská

Vorlı́čková

et al. 2012

Chemistry A European J

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Aptamer-based biosensors offer promising perspectives for high performance, specific detection of proteins. The thrombin binding aptamer (TBA) is a G-quadruplex-forming DNA sequence, which is frequently elongated at one end to increase its analytical performances in a biosensor configuration. Herein, we investigate how the elongation of TBA at its 5' end affects its structure and stability. Circular dichroism spectroscopy shows that TBA folds in an antiparallel G-quadruplex conformation with all studied cations (Ba(2+), Ca(2+), K(+), Mg(2+), Na(+), NH(4)(+), Sr(2+) and the [Ru(NH(3))(6)](2+/3+) redox marker) whereas other structures are adopted by the elongated aptamers in the presence of some of these cations. The stability of each structure is evaluated on the basis of UV spectroscopy melting curves. Thermal difference spectra confirm the quadruplex character of all conformations. The elongated sequences can adopt a parallel or an antiparallel structure, depending on the nature of the cation; this can potentially confer an ion-sensitive switch behavior. This switch property is demonstrated with the frequently employed redox complex [Ru(NH(3))(6)](3+), which induces the parallel conformation at very low concentrations (10 equiv per strand). The addition of large amounts of K(+) reverts the conformation to the antiparallel form, and opens interesting perspectives for electrochemical biosensing or redox-active responsive devices.

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Oligonucleotide‐Based Luminescent Detection of Metal Ions

Cited by 83 publications

References 157 publications

Graphene and Other Nanomaterial-Based Electrochemical Aptasensors

Graphene and Other Nanomaterial-Based Electrochemical Aptasensors

Improved performances of catalytic G-quadruplexes (G4-DNAzymes) via the chemical modifications of the DNA backbone to provide G-quadruplexes with double 3′-external G-quartets

Elongated Thrombin Binding Aptamer: A G‐Quadruplex Cation‐Sensitive Conformational Switch

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