Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Electrical wiring of Shewanella oneidensis MR-1 with osmium polymers of different redox potentials

Tavakoli, Laleh LU (2021) KEMR16 20131
Department of Chemistry
Theoretical Chemistry
Abstract
The results of studies have shown that the several applications such as microbial electrochemical system (MES), bio-electrochemical systems (BESs) and production of beneficial chemicals are due to electrochemical connection among electrodes and microorganisms. The following two factors are important in choosing the microbe mediated electrochemical biosensors: I) Binding of bacterial cells on the electrode, II) Efficient electron transfer (EET) between the electrode and the cells by a mediator.
In this study, gram-negative bacterium Shewanella oneidensis MR-1 was used in MES due to its unique characteristic features such as metal ion-reducing bacterium and direct ET capability. Osmium redox polymers (ORPs) were acted as efficient electron... (More)
The results of studies have shown that the several applications such as microbial electrochemical system (MES), bio-electrochemical systems (BESs) and production of beneficial chemicals are due to electrochemical connection among electrodes and microorganisms. The following two factors are important in choosing the microbe mediated electrochemical biosensors: I) Binding of bacterial cells on the electrode, II) Efficient electron transfer (EET) between the electrode and the cells by a mediator.
In this study, gram-negative bacterium Shewanella oneidensis MR-1 was used in MES due to its unique characteristic features such as metal ion-reducing bacterium and direct ET capability. Osmium redox polymers (ORPs) were acted as efficient electron transfer (EET) mediators to direct the electrochemical flow of biomaterials to electrods.
In the present study, the effect of the formal potential (E0') of three flexible osmium redox polymers was investigated: [Os(4,4'-dimethoxy-2,2'-bipyridine)2(PVI)Cl]+ ([Os-DMOPVI]); [Os(4,4'-dimethyl-2,2'-bipyridine)2(PVI)Cl]+ ([Os-DMPVI]); and [Os(4,4'-dichloro-2,2'- bipyridine)2(PVI)Cl]+ ([Os-DCPVI]). The electron donating or withdrawing ability of the functional group on the bipyridyl ligands coordinated to the osmium redox center can greatly affect the Os (II/III) redox potential.
Our results demonstrated that out of the three polymers, Os-DMPVI with E0' of +121 mV vs Ag|AgCl|KCl(sat.) had the greatest ability to produce electrical energy in the presence of lactate as a substrate because of the methyl functional group. Os-DMPVI polymer modified graphite electrode connected with S. oneidensis MR-1 exhibited a current density of 13.62 μA cm2 with a significant decrease in the start-up time for electrocatalysis. (Less)
Popular Abstract
A great deal of microbial electrochemical system (MES) and microbial biosensors are the results of electrochemical connection between microorganisms and electrodes.
In the present thesis, the extracellular electron transfer (EET) from a biomaterial is studied. Shewanella oneidensis MR-1 was used in MES due to its unique charateristic Features: I) Metal ion reducing bacterium, II) Direct electron transfer ET competence.
The efficiency of ET was increased by using the covered Osmium redox polymers (ORPs) as an efficient ET mediator.
We have shown in our results that current density could be increased by this bacterium. In addition, a major decrease in the start-up time for electrocatalysis was observed. The extracellular electron transfer... (More)
A great deal of microbial electrochemical system (MES) and microbial biosensors are the results of electrochemical connection between microorganisms and electrodes.
In the present thesis, the extracellular electron transfer (EET) from a biomaterial is studied. Shewanella oneidensis MR-1 was used in MES due to its unique charateristic Features: I) Metal ion reducing bacterium, II) Direct electron transfer ET competence.
The efficiency of ET was increased by using the covered Osmium redox polymers (ORPs) as an efficient ET mediator.
We have shown in our results that current density could be increased by this bacterium. In addition, a major decrease in the start-up time for electrocatalysis was observed. The extracellular electron transfer abilities of electrogens combined with such polymers could increase electrocatalysis.
In this thesis we have studied the effect of the formal potential (E0') of three flexible osmium redox polymers with efficient electron shuttling properties combined with the polymeric structure. The efficiency of electrical wiring from gram-negative bacterium; S. oneidensis MR-1 was investigated on these three different polymers.
Os-DMPVI had the greatest ability to produce electrical energy in the presence of lactate. Our results showed that S. oneidensis MR-1 presents a good mediator to be wired to the osmium redox polymers with methyl functional group over the graphite electrode surface. (Less)
Please use this url to cite or link to this publication:
author
Tavakoli, Laleh LU
supervisor
organization
course
KEMR16 20131
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Analytical Chemistry, Bio-Analytical Chemistry, Electrochemistry, Bacteria, Osmium redox polymers, Shewanella Oneidensis MR-1, electrode, Microbial electrosynthesis, Electron transfer
language
English
id
9032500
date added to LUP
2021-05-05 11:42:01
date last changed
2021-05-05 11:42:01
@misc{9032500,
  abstract     = {{The results of studies have shown that the several applications such as microbial electrochemical system (MES), bio-electrochemical systems (BESs) and production of beneficial chemicals are due to electrochemical connection among electrodes and microorganisms. The following two factors are important in choosing the microbe mediated electrochemical biosensors: I) Binding of bacterial cells on the electrode, II) Efficient electron transfer (EET) between the electrode and the cells by a mediator.
In this study, gram-negative bacterium Shewanella oneidensis MR-1 was used in MES due to its unique characteristic features such as metal ion-reducing bacterium and direct ET capability. Osmium redox polymers (ORPs) were acted as efficient electron transfer (EET) mediators to direct the electrochemical flow of biomaterials to electrods.
In the present study, the effect of the formal potential (E0') of three flexible osmium redox polymers was investigated: [Os(4,4'-dimethoxy-2,2'-bipyridine)2(PVI)Cl]+ ([Os-DMOPVI]); [Os(4,4'-dimethyl-2,2'-bipyridine)2(PVI)Cl]+ ([Os-DMPVI]); and [Os(4,4'-dichloro-2,2'- bipyridine)2(PVI)Cl]+ ([Os-DCPVI]). The electron donating or withdrawing ability of the functional group on the bipyridyl ligands coordinated to the osmium redox center can greatly affect the Os (II/III) redox potential.
Our results demonstrated that out of the three polymers, Os-DMPVI with E0' of +121 mV vs Ag|AgCl|KCl(sat.) had the greatest ability to produce electrical energy in the presence of lactate as a substrate because of the methyl functional group. Os-DMPVI polymer modified graphite electrode connected with S. oneidensis MR-1 exhibited a current density of 13.62 μA cm2 with a significant decrease in the start-up time for electrocatalysis.}},
  author       = {{Tavakoli, Laleh}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Electrical wiring of Shewanella oneidensis MR-1 with osmium polymers of different redox potentials}},
  year         = {{2021}},
}