67 research outputs found
Inā situ Biofilm Quantification in Bioelectrochemical Systems by using Optical Coherence Tomography
Detailed studies of microbial growth in bioelectrochemical systems (BESs) are required for their suitable design and operation. Here, we report the use of optical coherence tomography (OCT) as a tool for inā
situ and noninvasive quantification of biofilm growth on electrodes (bioanodes). An experimental platform is designed and described in which transparent electrodes are used to allow realātime, 3D biofilm imaging. The accuracy and precision of the developed method is assessed by relating the OCT results to wellāestablished standards for biofilm quantification (chemical oxygen demand (COD) and total N content) and show high correspondence to these standards. Biofilm thickness observed by OCT ranged between 3 and 90ā
Ī¼m for experimental durations ranging from 1 to 24ā
days. This translated to growth yields between 38 and 42ā
mgurn:x-wiley:18645631:media:cssc201800589:cssc201800589-math-0001 āgurn:x-wiley:18645631:media:cssc201800589:cssc201800589-math-0002 ā1 at an anode potential of ā0.35ā
V versus Ag/AgCl. Timeālapse observations of an experimental run performed in duplicate show high reproducibility in obtained microbial growth yield by the developed method. As such, we identify OCT as a powerful tool for conducting inādepth characterizations of microbial growth dynamics in BESs. Additionally, the presented platform allows concomitant application of this method with various optical and electrochemical techniques
A Natural Route to Nanowires and Energy Storage
Organic electronics is a burgeoning area, with a growing range of applications. This new research ā in which nanowires are grown naturally rather then synthesized chemically ā may provide new methods for biologically-produced or biologically-inspired materials for sustainable nanomanufacturing. Pilin nanofilaments (pili) ā known now as microbial nanowires ā are a class of fibrous proteins found in the sediment bacteria Geobacter. Temperature studies find metallic characteristics. The conductivity can be modulated by doping or by using an applied voltage in an electrochemical transistor configuration, showing the potential for device applications, including supercapacitors for energy storage
Going the Distance: Long-Range Conductivity in Protein and Peptide Bioelectronic Materials.
Bioelectronic materials interface biomolecules, cells, organs, or organisms with electronic devices, and they represent an active and growing field of materials research. Protein and peptide nanostructures are ideal bioelectronic materials. They possess many of the properties required for biocompatibility across scales from enzymatic to organismal interfaces, and recent examples of supramolecular protein and peptide nanostructures exhibit impressive electronic properties. The ability of such natural and synthetic protein and peptide materials to conduct electricity over micrometer to centimeter length scales, however, is not readily understood from a conventional view of their amino acid building blocks. Distinct in structure and properties from solid-state inorganic and synthetic organic metals and semiconductors, supramolecular conductive proteins and peptides require careful theoretical treatment and experimental characterization methods to understand their electronic structure. In this review, we discuss theory and experimental evidence from recent literature describing the long-range conduction of electronic charge in protein and peptide materials. Electron transfer across proteins has been studied extensively, but application of models for such short-range charge transport to longer distances relevant to bioelectronic materials are less well-understood. Implementation of electronic band structure and electron transfer formulations in extended biomolecular systems will be covered in the context of recent materials discoveries and efforts at characterization of electronic transport mechanisms
- ā¦