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Cultivation of Exoelectrogenic Bacteria in Conductive DNA Nanocomposite Hydrogels Yields a Programmable Biohybrid Materials System
Publikationstyp
Journal Article
Date Issued
2020-04-01
Sprache
English
Volume
12
Issue
13
Start Page
14806
End Page
14813
Citation
ACS Applied Materials and Interfaces 12 (13): 14806-14813 (2020-04-01)
Publisher DOI
Scopus ID
PubMed ID
32191028
The use of living microorganisms integrated within electrochemical devices is an expanding field of research, with applications in microbial fuel cells, microbial biosensors or bioreactors. We describe the use of porous nanocomposite materials prepared by DNA polymerization of carbon nanotubes (CNTs) and silica nanoparticles (SiNPs) for the construction of a programmable biohybrid system containing the exoelectrogenic bacterium Shewanella oneidensis. We initially demonstrate the electrical conductivity of the CNT-containing DNA composite by employment of chronopotentiometry, electrochemical impedance spectroscopy, and cyclic voltammetry. Cultivation of Shewanella oneidensis in the conductive materials shows that the exoelectrogenic bacteria populate the matrix of the conductive composite, while nonexoelectrogenic Escherichia coli remain on its surface. Moreover, the ability to use extracellular electron transfer pathways is positively correlated with the number of cells within the conductive synthetic biofilm matrix. The Shewanella-containing composite remains stable for several days and shows electrochemical activity, indicating that the conductive backbone is capable of extracting the metabolic electrons produced by the bacteria under strictly anoxic conditions and conducting them to the anode. Programmability of this biohybrid material system is demonstrated by on-demand release and degradation induced by a short-term enzymatic stimulus. We believe that the application possibilities of such biohybrid materials could even go beyond microbial biosensors, bioreactors, and fuel cell systems.
Subjects
Carbon nanotubes
DNA
extracellular electron transfer
nanocomposites
rolling circle amplification
Shewanella
silica nanoparticles