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Voltammetric Study of the Influence of Various Phosphate Anions on Silver Nanoparticle Oxidation.

Navolotskaya DV, Toh HS, Batchelor-McAuley C, Compton RG - ChemistryOpen (2015)

Bottom Line: The three different species of anions were found to have a varying degree of influence on silver oxidation with the order PO4 (3-)>HPO4 (2-)>H2PO4 (-).It was found that in the presence of phosphate anions, the silver oxidation potential shifts to a less positive value, which indicated the increasing ease of the oxidation reaction of silver.Given that the interplay between silver and its cation is crucial to its antibacterial properties and significant concentrations of the HPO4 (2-) anion are present at biological pH (near neutral), it is essential that the influence of the dibasic anion (HPO4 (2-)) on silver oxidation dynamics be considered for biological systems.

View Article: PubMed Central - PubMed

Affiliation: Saint Petersburg State University Universitetskaya nab.7-9, Saint Petersburg, 199034, Russia.

ABSTRACT
The antibacterial properties of silver are strongly controlled by the redox couple of silver/silver(I). This work reports the influence of phosphate anions on silver nanoparticle oxidation, which is important given the abundance of phosphate species in biological systems. The three different species of anions were found to have a varying degree of influence on silver oxidation with the order PO4 (3-)>HPO4 (2-)>H2PO4 (-). It was found that in the presence of phosphate anions, the silver oxidation potential shifts to a less positive value, which indicated the increasing ease of the oxidation reaction of silver. Given that the interplay between silver and its cation is crucial to its antibacterial properties and significant concentrations of the HPO4 (2-) anion are present at biological pH (near neutral), it is essential that the influence of the dibasic anion (HPO4 (2-)) on silver oxidation dynamics be considered for biological systems.

No MeSH data available.


A close up of cyclic voltammogram representing the oxidation of silver nanoparticles on a glassy carbon electrode at a scan rate of 0.05 V s−1. Black: scan in 0.1 m NaNO3. Red: 0.0125 m Na3PO4 and 0.0875 m NaNO3. Green: 0.025 m Na3PO4 and 0.075 m NaNO3. Blue: 0.05 m Na3PO4 and 0.05 m NaNO3. Dark yellow: 0.1 m Na3PO4. Purple: 0.2 m Na3PO4. Orange: 0.3 m Na3PO4. Each data point consists of a minimum of three repeats.
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fig02: A close up of cyclic voltammogram representing the oxidation of silver nanoparticles on a glassy carbon electrode at a scan rate of 0.05 V s−1. Black: scan in 0.1 m NaNO3. Red: 0.0125 m Na3PO4 and 0.0875 m NaNO3. Green: 0.025 m Na3PO4 and 0.075 m NaNO3. Blue: 0.05 m Na3PO4 and 0.05 m NaNO3. Dark yellow: 0.1 m Na3PO4. Purple: 0.2 m Na3PO4. Orange: 0.3 m Na3PO4. Each data point consists of a minimum of three repeats.

Mentions: First, the behaviour of silver nanoparticles in trisodium phosphate solutions (Na3PO4) was studied. A voltammogram was recorded in 0.0125 m solution of Na3PO4 containing 0.0875 m NaNO3. As can be seen from the red line of Figure 2, the silver oxidation peak shifted negatively as compared with the control experiment in the absence of any phosphate ions (black line of Figure 2). The voltammetric signal obtained in the absence of phosphate ions (black line) corresponds to silver oxidation to its cation, Ag+.6a The experiment was repeated using solutions of higher Na3PO4 concentrations.


Voltammetric Study of the Influence of Various Phosphate Anions on Silver Nanoparticle Oxidation.

Navolotskaya DV, Toh HS, Batchelor-McAuley C, Compton RG - ChemistryOpen (2015)

A close up of cyclic voltammogram representing the oxidation of silver nanoparticles on a glassy carbon electrode at a scan rate of 0.05 V s−1. Black: scan in 0.1 m NaNO3. Red: 0.0125 m Na3PO4 and 0.0875 m NaNO3. Green: 0.025 m Na3PO4 and 0.075 m NaNO3. Blue: 0.05 m Na3PO4 and 0.05 m NaNO3. Dark yellow: 0.1 m Na3PO4. Purple: 0.2 m Na3PO4. Orange: 0.3 m Na3PO4. Each data point consists of a minimum of three repeats.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608526&req=5

fig02: A close up of cyclic voltammogram representing the oxidation of silver nanoparticles on a glassy carbon electrode at a scan rate of 0.05 V s−1. Black: scan in 0.1 m NaNO3. Red: 0.0125 m Na3PO4 and 0.0875 m NaNO3. Green: 0.025 m Na3PO4 and 0.075 m NaNO3. Blue: 0.05 m Na3PO4 and 0.05 m NaNO3. Dark yellow: 0.1 m Na3PO4. Purple: 0.2 m Na3PO4. Orange: 0.3 m Na3PO4. Each data point consists of a minimum of three repeats.
Mentions: First, the behaviour of silver nanoparticles in trisodium phosphate solutions (Na3PO4) was studied. A voltammogram was recorded in 0.0125 m solution of Na3PO4 containing 0.0875 m NaNO3. As can be seen from the red line of Figure 2, the silver oxidation peak shifted negatively as compared with the control experiment in the absence of any phosphate ions (black line of Figure 2). The voltammetric signal obtained in the absence of phosphate ions (black line) corresponds to silver oxidation to its cation, Ag+.6a The experiment was repeated using solutions of higher Na3PO4 concentrations.

Bottom Line: The three different species of anions were found to have a varying degree of influence on silver oxidation with the order PO4 (3-)>HPO4 (2-)>H2PO4 (-).It was found that in the presence of phosphate anions, the silver oxidation potential shifts to a less positive value, which indicated the increasing ease of the oxidation reaction of silver.Given that the interplay between silver and its cation is crucial to its antibacterial properties and significant concentrations of the HPO4 (2-) anion are present at biological pH (near neutral), it is essential that the influence of the dibasic anion (HPO4 (2-)) on silver oxidation dynamics be considered for biological systems.

View Article: PubMed Central - PubMed

Affiliation: Saint Petersburg State University Universitetskaya nab.7-9, Saint Petersburg, 199034, Russia.

ABSTRACT
The antibacterial properties of silver are strongly controlled by the redox couple of silver/silver(I). This work reports the influence of phosphate anions on silver nanoparticle oxidation, which is important given the abundance of phosphate species in biological systems. The three different species of anions were found to have a varying degree of influence on silver oxidation with the order PO4 (3-)>HPO4 (2-)>H2PO4 (-). It was found that in the presence of phosphate anions, the silver oxidation potential shifts to a less positive value, which indicated the increasing ease of the oxidation reaction of silver. Given that the interplay between silver and its cation is crucial to its antibacterial properties and significant concentrations of the HPO4 (2-) anion are present at biological pH (near neutral), it is essential that the influence of the dibasic anion (HPO4 (2-)) on silver oxidation dynamics be considered for biological systems.

No MeSH data available.