scholarly journals The Hydrogen Electrode-Silver Chloride Electrode System at High Temperatures and Pressures1

1955 ◽  
Vol 77 (5) ◽  
pp. 1344-1346 ◽  
Author(s):  
M. H. Lietzke
Keyword(s):  
High Temperatures ◽  
Silver Chloride ◽  
Electrode System ◽  
Hydrogen Electrode ◽  
Silver Chloride Electrode

scholarly journals Metabolic Current Production by an Oral Biofilm Pathogen Corynebacterium matruchotii

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3141
Author(s):  
Divya Naradasu ◽  
Waheed Miran ◽  
Akihiro Okamoto
Keyword(s):  
Metabolic Activity ◽  
High Resolution Mass Spectrometry ◽  
Electrode System ◽  
Human Pathogens ◽  
Oral Biofilm ◽  
Hydrogen Electrode ◽  
Production Capability ◽  
Current Production ◽  
The Impact ◽  
Microbial Metabolic Activity

The development of a simple and direct assay for quantifying microbial metabolic activity is important for identifying antibiotic drugs. Current production capabilities of environmental bacteria via the process called extracellular electron transport (EET) from the cell interior to the exterior is well investigated in mineral-reducing bacteria and have been used for various energy and environmental applications. Recently, the capability of human pathogens for producing current has been identified in different human niches, which was suggested to be applicable for drug assessment, because the current production of a few strains correlated with metabolic activity. Herein, we report another strain, a highly abundant pathogen in human oral polymicrobial biofilm, Corynebacterium matruchotii, to have the current production capability associated with its metabolic activity. It showed the current production of 50 nA/cm2 at OD600 of 0.1 with the working electrode poised at +0.4 V vs. a standard hydrogen electrode in a three-electrode system. The addition of antibiotics that suppress the microbial metabolic activity showed a significant current decrease (>90%), establishing that current production reflected the cellular activity in this pathogen. Further, the metabolic fixation of atomically labeled 13C (31.68% ± 2.26%) and 15N (19.69% ± 1.41%) confirmed by high-resolution mass spectrometry indicated that C. matruchotii cells were metabolically active on the electrode surface. The identified electrochemical activity of C. matruchotii shows that this can be a simple and effective test for evaluating the impact of antibacterial compounds, and such a method might be applicable to the polymicrobial oral biofilm on electrode surfaces, given four other oral pathogens have already been shown the current production capability.

Electrochemical investigation of hapten-antibody interactions by differential pulse polarography.

1982 ◽  
Vol 28 (9) ◽  
pp. 1968-1972 ◽  
Author(s):  
K R Wehmeyer ◽  
H B Halsall ◽  
W R Heineman
Keyword(s):  
Specific Antibody ◽  
Silver Chloride ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Potential Range ◽  
Peak Current ◽  
Silver Chloride Electrode ◽  
Pulse Polarography ◽  
Silver Silver ◽  
Silver Silver Chloride

Abstract The binding of electroactively labeled estriol with estrogen-specific antibody and its subsequent displacement by unlabeled estriol have been monitored by differential pulse polarography. Estriol was found to be electro-inactive in the potential range -200 mV to -1000 mV vs a silver/silver chloride electrode. Estriol labeled in the 2 and 4 position with nitro groups was electroactive, giving two reduction waves at -422 mV and -481 mV vs a silver/silver chloride electrode. The peak current was linear with concentration over the range 60 micrograms/L to 3.7 mg/L. The addition of aliquots of estrogen-specific antibody reduced the peak current proportionately, indicating the binding of ligand to specific antibody. Subsequent addition of unlabeled estriol produced incremental increases in peak reduction current, indicating competitive and reversible binding of the two ligands for the antibody. Separation of bound from free labeled hapten was not necessary because reduction of the antibody-bound labeled estriol is attenuated at the electrode.

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