Tools and Tactics for the Optical Detection of Mercuric Ion

Nolan, Elizabeth M.; Lippard, Stephen J.

doi:10.1021/cr068000q

Cited by 2,231 publications

(1,090 citation statements)

References 223 publications

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“…Mercury is a highly toxic heavy metal and its detection has attracted a lot of research efforts. 29 A recent development is the use of thymine-rich DNA for Hg 2+ binding. 30 In this work, we immobilized a Hg 2+ binding DNA ( Figure 1A) into a hydrogel microparticle to achieve fast visual detection ( Figure 1B).…”

Section: Resultsmentioning

confidence: 99%

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

Helwa

Dave

Froidevaux

et al. 2012

ACS Appl. Mater. Interfaces

120

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These authors contributed equally to the work. AbstractWith a low optical background, high loading capacity, and good biocompatibility, hydrogels are ideal materials for immobilization of biopolymers to develop optical biosensors. We recently immobilized mercury and lead binding DNAs within a monolithic gel and demonstrated ultra-sensitive visual detection of these heavy metals. The high sensitivity was attributed to the enrichment of the analytes into the gels.The signaling kinetics was slow, however, taking about one hour to obtain a stable optical signal due to a long diffusion distance. In this work we aim to understand the analyte enrichment process and improve the signaling kinetics by preparing hydrogel microparticles. DNA-functionalized gel beads were synthesized using an emulsion polymerization technique and most of the beads were between 10 and 50 μm. Acrydite-modified DNA was incorporated by co-polymerization. Visual detection of 10 nM Hg 2+ was still achieved and a stable signal was obtained in just two minutes. The gel beads could be spotted to form a microarray and dried for storage. A new visual sensor for adenosine was designed and immobilized within the gel beads. The adenosine aptamer binds its target about 1000-fold less tightly compared to the mercury binding DNA, allowing a comparison to be made on analyte enrichment by aptamer-functionalized hydrogels.

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Section: Resultsmentioning

confidence: 99%

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

Helwa

Dave

Froidevaux

et al. 2012

ACS Appl. Mater. Interfaces

120

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“…In order to provide on-site analysis, a number of metal sensing platforms have been developed. [2][3][4][5][6][7][8][9][10][11] DNAzymes are DNA-based catalysts obtained through in vitro selection. [12][13][14][15][16] Owing to their high catalytic efficiency and versatility in sensor design, RNA-cleaving DNAzymes have emerged as a unique metal sensing platform.…”

Section: Introductionmentioning

confidence: 99%

Sensing Parts-per-Trillion Cd²⁺, Hg²⁺, and Pb²⁺ Collectively and Individually Using Phosphorothioate DNAzymes

2014

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Cadmium, mercury and lead are collectively banned by many countries and regions in electronic devices due to their extremely high toxicity. To date, no sensing method can detect them as a group and also individually with sufficient sensitivity and selectivity. An RNA-cleaving DNAzyme (Ce13d) was recently reported to be active with trivalent lanthanides, which are hard Lewis acids. In this work, phosphorothioate (PS) modifications were systematically made on Ce13d. A single PS at the substrate cleavage site shifts the activity from being dependent on lanthanide to soft thiophilic metals.By incorporating the PS modification to a few other DNAzymes, a sensor array was prepared to detect each metal. Individual sensors have excellent sensitivity (limit of detection = 4.8 nM Cd 2+ , 2.0 nM Hg 2+ , and 0.1 nM Pb 2+ ). This study provides a new route to obtain metal-specific DNAzymes by atomic replacement and also offers important mechanistic insights into metal binding and DNAzyme catalysis.3

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“…[25,26] To manage the mercury contamination problem, many sensors have been developed. [27] In particular, a large number of fluorescent, [15,[28][29][30] colorimetric, [31,32] and electrochemical sensors [33,34] have been designed based on the Hg II -thymine binding. In the original paper by Ono et al, [15] the DNA shown in Figure 1A was labeled with a 6-carboxyfluorescein (FAM) and a dark quencher (4-(4-dimethylaminophenyl) diazenylbenzoic acid, Dabcyl), respectively on the two ends.…”

Section: Introductionmentioning

confidence: 99%

Metal‐Induced Specific and Nonspecific Oligonucleotide Folding Studied by FRET and Related Biophysical and Bioanalytical Implications

Kiy

Jacobi

Liu

2011

Chemistry A European J

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Abstract.Metal induced nucleic acid folding has been extensively studied with ribozymes, DNAzymes, tRNA and riboswitches. These RNA/DNA molecules usually have a high content of double-stranded regions to support a rigid scaffold. On the other hand, such rigid structural features are not available for many in vitro selected or rationally designed DNA aptamers; they adopt flexible random coil structures in the absence of target molecules. Upon target binding, these aptamers adaptively fold into a compact structure with a reduced end-to-end distance, making fluorescence resonance energy transfer (FRET) a popular signaling mechanism. However, non-specific folding induced by mono-or divalent metal ions can also reduce the end-to-end distance and thus lead to false positive results. In this study we used a FRET pair labeled Hg II binding DNA and monitored metal induced folding in the presence of various cations. While non-specific electrostatically mediated folding can be very significant, at each tested salt condition, Hg II induced folding was still observed with a similar sensitivity. We also studied the biophysical meaning of the acceptor/donor fluorescence ratio that allowed us to explain the experimental observations. Potential solutions for this ionic strength problem have been discussed. For example, probes designed to signaling the formation of double-stranded DNA showed a lower dependency on ionic strength.3

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Tools and Tactics for the Optical Detection of Mercuric Ion

Cited by 2,231 publications

References 223 publications

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

Sensing Parts-per-Trillion Cd²⁺, Hg²⁺, and Pb²⁺ Collectively and Individually Using Phosphorothioate DNAzymes

Metal‐Induced Specific and Nonspecific Oligonucleotide Folding Studied by FRET and Related Biophysical and Bioanalytical Implications

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Tools and Tactics for the Optical Detection of Mercuric Ion

Cited by 2,231 publications

References 223 publications

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

Sensing Parts-per-Trillion Cd2+, Hg2+, and Pb2+ Collectively and Individually Using Phosphorothioate DNAzymes

Metal‐Induced Specific and Nonspecific Oligonucleotide Folding Studied by FRET and Related Biophysical and Bioanalytical Implications

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Product

Resources

About

Sensing Parts-per-Trillion Cd²⁺, Hg²⁺, and Pb²⁺ Collectively and Individually Using Phosphorothioate DNAzymes