A Simple Determination of the Ag2O Solubility Product by Potentiometric Determinations of Both Ag+1 and OH–1

Sauls, Frederick C.

doi:10.1021/ed300586g

Cited by 10 publications

(10 citation statements)

References 27 publications

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“…44 The solubility limit of Ag + is about 1 mM at pH 9. 45 Therefore, we were far below this limit in the above experiments, and Ag+ precipitation was not a concern here. Next, we tested various concentrations of Ag + at pH 7.0 in 25 mM NaNO3 by measuring the cleavage yield at 5 min.…”

Section: Resultsmentioning

confidence: 81%

A Silver DNAzyme

2016

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Silver is a very common heavy metal, and its detection is of significant analytical importance.DNAzymes are DNA-based catalysts; they typically recruit divalent and trivalent metal ions for catalysis. Herein, we report a silver-specific RNA-cleaving DNAzyme named Ag10c obtained after six rounds of in vitro selection. Ag10c displays a catalytic rate of 0.41 min -1 with 10 µM Ag + at pH 7.5 with 200 mM NaNO3, while its activity is completely inhibited with the same concentration of NaCl. Ag10c is highly specific for Ag + among all the tested metals. A catalytic beacon biosensor is designed by labeling a fluorophore and a quencher on the DNAzyme.Fluorescence enhancement is observed in the presence of Ag + with a detection limit of 24.9 nM Ag + . The sensor shows a similar analytical performance in Lake Huron water. This is the first monovalent transition metal dependent RNA-cleaving DNAzyme. Apart from its biosensor application, this study strengthens the idea of exploring beyond the traditional understanding of multivalent ion dependent DNAzyme catalysis.3

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Section: Resultsmentioning

confidence: 81%

A Silver DNAzyme

2016

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“…This observation can be explained by considering the Lewis base identity of thiosulfate. The solubility of Ag oxide is significantly increased in its presence, where the equilibrium constant K (calculated by multiplying K sp × K f ) of Ag-oxide in alkaline thiosulfate is 3.2 × 10 5 (compared to the value of 1.9 × 10 −8 in water 39 ). A more complete dissolution of Ag-oxide eliminates its adhesive contacts and lowers the rate of detected collisions for the alkaline thiosulfate condition in the absence of the sulfide adhesion layer.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Collision, Adhesion, and Oxidation of Single Ag Nanoparticles on a Polysulfide-Modified Microelectrode

Defnet

Zhang

2021

J. Am. Chem. Soc.

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We report the collision, adhesion, and oxidation behavior of single silver nanoparticles (Ag NPs) on a polysulfide-modified gold microelectrode. Despite its remarkable success in volume analysis for smaller Ag NPs, the method of NP-collision electrochemistry has failed to analyze particles greater than 50 nm due to uncontrollable collision behavior and incomplete NP oxidation. Herein, we describe the unique capability of an ultrathin polysulfide layer in controlling the collision behavior of Ag NPs by drastically improving their sticking probability on the electrode. The ultrathin sulfurous layer is formed on gold by sodium thiosulfate electro-oxidation and serves both as an adhesive interface for colliding NPs and as a preconcentrated reactive medium to chemically oxidize Ag to form Ag2S. Rapid particle dissolution is further promoted by the presence of bulk sodium thiosulfate serving as a Lewis base, which drastically improves the solubility of generated Ag2S by a factor of 1013. The combined use of polysulfide and sodium thiosulfate allows us to observe a 25× increase in NP detection frequency, a 3× increase in peak amplitude, and more complete oxidation for larger Ag NPs. By recognizing how volumetric analysis using transmission electron microscopy (TEM) may overestimate quasi-spherical NPs, we believe we can have full NP oxidation for particles up to 100 nm. By focusing on the electrode/solution interface for more effective NP-electrode contact, we expect that the knowledge learned from this study will greatly benefit future NP collision systems for mechanistic studies in single-entity electrochemistry as well as designing ultrasensitive biochemical sensors.

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“…As we known, H 2 Q would usually react with Ag + to produce Ag atoms and BQ. However, the redox reaction in aqueous solution at room temperature is dominated by the autoxidation of H 2 Q and the generation of silver hydroxide (AgOH). , The side reactions, which accompany the main reaction, would deeply influence the process of the reaction. For instance, H 2 Q would autoxidize in acidic solution to form H 2 O 2 and block the generation of Ag atoms.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the production of Ag 2 O would not be neglected. Therefore, the half reaction for Ag + and Ag would not be written as eq since Ag + would first react with OH – …”

Section: Resultsmentioning

confidence: 99%

“…Both TEM images and the peak shifts exhibited that H 2 Q would react with silver nitrate at basic pH, and the freshly formed silver nanoparticles would more easily form a core–shell structure as pH increases. On the other hand, the side reaction of H 2 Q, such as the autoxidation, the coupling of quinhydrone, , and the formation of AgOH, would gradually convert the electrode potential and reaction kinetics of H 2 Q and Ag + . The calculation methodology would be discussed later in the section of reaction kinetics.…”

Section: Resultsmentioning

confidence: 99%

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pH-Response Mechanism of a Redox Reaction between Silver Ions and Hydroquinone

Xie¹,

Jing²,

Li³

et al. 2016

J. Phys. Chem. C

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Studying chemical reactions at the nanoscale level could aid to better understand and control reaction processes. In this paper, the redox reaction between hydroquinone and Ag + via gold nanoparticles as a suitable surface was taken as an example, where its thermochemical values were computed by using density functional theory (DFT) methods with the 6-31G(d) basis set. The calculated results exhibited that the reaction kinetics was related to pH values and concluded as three different kinds of processes. Assisted by the gold nanoparticles, we tracked the reduction of Ag + in real time by plasmon resonance Rayleigh scattering spectroscopy and dark-field microscopy. Moreover, discrete dipole approximation and transmission electron microscope images were also conducted, and the calculated results were in good agreement with the experimental ones. In addition, we utilized the pH response of the redox reaction to distinguish cancer cells from the normal ones, which showed promising applications in promoting the development of disease diagnosis.

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A Simple Determination of the Ag₂O Solubility Product by Potentiometric Determinations of Both Ag⁺¹ and OH^–1

Cited by 10 publications

References 27 publications

A Silver DNAzyme

A Silver DNAzyme

Collision, Adhesion, and Oxidation of Single Ag Nanoparticles on a Polysulfide-Modified Microelectrode

pH-Response Mechanism of a Redox Reaction between Silver Ions and Hydroquinone

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