Immobilization of a Catalytic DNA Molecular Beacon on Au for Pb(II) Detection

Swearingen, Carla B.; Wernette, Daryl P.; Cropek, Donald M.; Lu, Yi; Sweedler, Jonathan V.; Bohn, Paul W.

doi:10.1021/ac0401016

Cited by 120 publications

(109 citation statements)

References 54 publications

(85 reference statements)

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“…For such a system, the selectivity for particular ions would be enhanced, since it will be determined by the product of the ability to separate the desired metal cation from interfering metal ions and the selectivity of the DNAzyme molecular recognition agent itself. The sensitivity and robust nature of the DNAzyme can also be improved by immobilizing the DNA within the NAI pores, instead of using it in solution (39). This platform offers the possibility of incorporating multiple sensing locations in one device; thus, by incorporating different metal-ion-selective DNAzymes into a single microfluidic device, multiple species can be determined simultaneously.…”

Section: +mentioning

confidence: 99%

Miniaturized Lead Sensor Based on Lead-Specific DNAzyme in a Nanocapillary Interconnected Microfluidic Device

Chang

Tulock

Liu

et al. 2005

Environ. Sci. Technol.

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123

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A miniaturized lead sensor has been developed by combining a lead-specific DNAzyme with a microfabricated device containing a network of microfluidic channels that are fluidically coupled via a nanocapillary array interconnect. A DNAzyme construct, selective for cleavage in the presence of Pb 2+ and derivatized with fluorophore (quencher) at the 5′ (3′) end of the substrate and enzyme strands, respectively, forms a molecular beacon that is used as the recognition element. The nanocapillary array membrane interconnect is used to manipulate fluid flows and deliver the small-volume sample to the beacon in a spatially confined detection window where the DNAzyme is interrogated using laser-induced fluorescence detection. A transformed log plot of the fluorescent signal exhibits a linear response (r 2 ) 0.982) over a Pb 2+ concentration range of 0.1-100 µM, and a detection limit of 11 nM. The sensor has been applied to the determination of Pb 2+ in an electroplating sludge reference material, the result agreeing with the certified value within 4.9%. Quantitative measurement of Pb 2+ in this complex sample demonstrates the selectivity of this sensor scheme and points favorably to the application of such technologies to analysis of environmental samples. The unique combination of a DNAzyme with a microfluidic-nanofluidic hybrid device makes it possible to change the DNAzyme to select for other compounds of interest, and to incorporate multiple sensing systems within a single device for greater flexibility. This work represents the initial steps toward creation of a robust field sensor for lead in groundwater or drinking water.

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Section: +mentioning

confidence: 99%

Miniaturized Lead Sensor Based on Lead-Specific DNAzyme in a Nanocapillary Interconnected Microfluidic Device

Chang

Tulock

Liu

et al. 2005

Environ. Sci. Technol.

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123

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“…Aptamers have been developed which bind small organic molecules (Hirao et al, 1997;Babendure et al, 2003;Sazani et al, 2004;Chu et al, 2006;Liu and Lu, 2006), proteins (Ruckman et al, 1998;Jayasena, 1999;Srisawat and Engelke, 2001; Lee et al, 2004), heavy metal ions (Chang et al, 2005;Swearingen et al, 2005;Wrzesinski and Ciesiolka, 2005;Stefan et al, 2006;Wernette et al, 2007) and even viruses (Gopinath et al, 2006a,b). Aptamers are best known as ligands to proteins, rivaling antibodies in both affinity and specificity (Jayasena, 1999), and aptamer-based therapeutics are now emerging (Ruckman et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Engineered 5S ribosomal RNAs displaying aptamers recognizing vascular endothelial growth factor and malachite green

Xing

Potty

Jackson

et al. 2009

J of Molecular Recognition

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In previous work, Vibrio proteolyticus 5S rRNA was shown to stabilize 13-50 nucleotide "guest" RNA sequences for expression in Escherichia coli. The expressed chimeric RNAs accumulated to high levels in E. coli without being incorporated into ribosomes and without obvious effects on the host cells. In this work, we inserted sequences encoding known aptamers recognizing a protein and an organic dye into the 5S rRNA carrier and showed that aptamer function is preserved in the chimeras. A surface plasmon resonance competitive binding assay demonstrated that a vascular endothelial growth factor (VEGF) aptamer/5S rRNA chimera produced in vitro by transcriptional runoff could compete with a DNA aptamer for VEGF, implying binding of the growth factor by the VEGF "ribosomal RNA aptamer." Separately, a 5S rRNA chimera displaying an aptamer known to increase the fluorescence of malachite green (MG) also enhanced MG fluorescence. Closely related control rRNA molecules showed neither activity. The MG aptamer/5S rRNA chimera, like the original MG aptamer, also increased the fluorescence of other triphenyl methane (TPM) dyes such as crystal violet, methyl violet, and brilliant green, although less effectively than with MG. These results indicate that the molecular recognition properties of aptamers are not lost when they are expressed in the context of a stable 5S rRNA carrier. Inclusion of the aptamer in a carrier may facilitate production of large quantities of RNA aptamers, and may open an approach to screening aptamer libraries in vivo.

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“…Of these, [8][9][10][11][12][13][14][15][16][17] DNAzyme has attracted much more attention. They have been extensively explored for Pb 2+ detection via fluorescence [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], fluorescence anisotropy [30], colorimetry [31][32][33][34], electrochemistry [35][36][37][38], electrochemiluminescence [39], dynamic light scattering [40,41], and surface enhanced Raman scattering [42].…”

Section: Introductionmentioning

confidence: 99%

A sensitive fluorescence anisotropy method for detection of lead (II) ion by a G-quadruplex-inducible DNA aptamer

Zhang

Meng

et al. 2014

Analytica Chimica Acta

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h i g h l i g h t s• A fluorescence anisotropy approach for detection of Pb 2+ was developed.• The strategy was based on bindinginduced allosteric conformational change of aptamer probe.• The sensing mechanism was established by testing the photoinduced electron transfer interaction. in homogeneous solution by a G-rich thrombin binding aptamer (TBA). The TBA labeled with 6-carboxytetramethylrhodamine (TMR) at the seventh thymine nucleotide was used as a fluorescent probe for signaling Pb 2+ . It was found that the aptamer probe had a high FA in the absence of Pb 2+ . This is because the rotation of TMR is restricted by intramolecular interaction with the adjacent guanine bases, which results in photoinduced electron transfer (PET). When the aptamer probe binds to Pb 2+ to form G-quadruplex, the intramolecular interaction should be eliminated, resulting in faster rotation of the fluorophore TMR in solution. Therefore, FA of aptamer probe is expected to decrease significantly upon binding to Pb 2+ . Indeed, we observed a decrease in FA of aptamer probe upon Pb 2+ binding. Circular dichroism, fluorescence spectra, and fluorescence lifetime measurement were used to verify the reliability and reasonability of the sensing mechanism. By monitoring the FA change of the aptamer probe, we were able to real-time detect binding between the TBA probe and Pb 2+ . Moreover, the aptamer probe was exploited as a recognition element for quantification of Pb 2+ in homogeneous solution. The change in FA showed a linear response to Pb 2+ from 10 nM to 2.0 M, with 1.0 nM limit of detection. In addition, this sensing system exhibited good selectivity for Pb 2+ over other metal ions. The method is simple, quick and inherits the advantages of aptamer and FA.

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Immobilization of a Catalytic DNA Molecular Beacon on Au for Pb(II) Detection

Cited by 120 publications

References 54 publications

Miniaturized Lead Sensor Based on Lead-Specific DNAzyme in a Nanocapillary Interconnected Microfluidic Device

Miniaturized Lead Sensor Based on Lead-Specific DNAzyme in a Nanocapillary Interconnected Microfluidic Device

Engineered 5S ribosomal RNAs displaying aptamers recognizing vascular endothelial growth factor and malachite green

A sensitive fluorescence anisotropy method for detection of lead (II) ion by a G-quadruplex-inducible DNA aptamer

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