@article {3046, title = {Engineering Geobacter pili to produce metal:organic filaments.}, journal = {Biosens Bioelectron}, volume = {222}, year = {2023}, month = {2023 Feb 15}, pages = {114993}, abstract = {

The organized self-assembly of conductive biological structures holds promise for creating new bioelectronic devices. In particular, Geobacter sulfurreducens type IVa pili have proven to be a versatile material for fabricating protein nanowire-based devices. To scale the production of conductive pili, we designed a strain of Shewanella oneidensis that heterologously expressed abundant, conductive Geobacter pili when grown aerobically in liquid culture. S. oneidensis expressing a cysteine-modified pilin, designed to enhance the capability to bind to gold, generated conductive pili that self-assembled into biohybrid filaments in the presence of gold nanoparticles. Elemental composition analysis confirmed the filament-metal interactions within the structures, which were several orders of magnitude larger than previously described metal:organic filaments. The results demonstrate that the S. oneidensis chassis significantly advances the possibilities for facile conductive protein nanowire design and fabrication.

}, keywords = {Biosensing Techniques, Electron Transport, Fimbriae, Bacterial, Geobacter, Gold, Metal Nanoparticles}, issn = {1873-4235}, doi = {10.1016/j.bios.2022.114993}, author = {Szmuc, Eric and Walker, David J F and Kireev, Dmitry and Akinwande, Deji and Lovley, Derek R and Keitz, Benjamin and Ellington, Andrew} } @article {3044, title = {Microbial nanowires with genetically modified peptide ligands to sustainably fabricate electronic sensing devices.}, journal = {Biosens Bioelectron}, volume = {226}, year = {2023}, month = {2023 Apr 15}, pages = {115147}, abstract = {

Nanowires have substantial potential as the sensor component in electronic sensing devices. However, surface functionalization of traditional nanowire and nanotube materials with short peptides that increase sensor selectivity and sensitivity requires complex chemistries with toxic reagents. In contrast, microorganisms can assemble pilin monomers into protein nanowires with intrinsic conductivity from renewable feedstocks, yielding an electronic material that is robust and stable in applications, but also biodegradable. Here we report that the sensitivity and selectivity of protein nanowire-based sensors can be modified with a simple plug and play genetic approach in which a short peptide sequence, designed to bind the analyte of interest, is incorporated into the pilin protein that is microbially assembled into nanowires. We employed a scalable Escherichia coli chassis to fabricate protein nanowires that displayed either a peptide previously demonstrated to effectively bind ammonia, or a peptide known to bind acetic acid. Sensors comprised of thin films of the nanowires amended with the ammonia-specific peptide had a ca. 100-fold greater response to ammonia than sensors made with unmodified protein nanowires. Protein nanowires with the peptide that binds acetic acid yielded a 4-fold higher response than nanowires without the peptide. The protein nanowire-based sensors had greater responses than previously reported sensors fabricated with other nanomaterials. The results demonstrate that protein nanowires with enhanced sensor response for analytes of interest can be fabricated with a flexible genetic strategy that sustainably eliminates the energy, environmental, and health concerns associated with other common nanomaterials.

}, keywords = {Acetic Acid, Ammonia, Biosensing Techniques, Electronics, Fimbriae Proteins, Ligands, Nanowires, Peptides}, issn = {1873-4235}, doi = {10.1016/j.bios.2023.115147}, author = {Lekbach, Yassir and Ueki, Toshiyuki and Liu, Xiaomeng and Woodard, Trevor and Yao, Jun and Lovley, Derek R} } @article {3069, title = {Bioinspired bio-voltage memristors.}, journal = {Nat Commun}, volume = {11}, year = {2020}, month = {2020 Apr 20}, pages = {1861}, abstract = {

Memristive devices are promising candidates to emulate biological computing. However, the typical switching voltages (0.2-2 V) in previously described devices are much higher than the amplitude in biological counterparts. Here we demonstrate a type of diffusive memristor, fabricated from the protein nanowires harvested from the bacterium Geobacter sulfurreducens, that functions at the biological voltages of 40-100 mV. Memristive function at biological voltages is possible because the protein nanowires catalyze metallization. Artificial neurons built from these memristors not only function at biological action potentials (e.g., 100 mV, 1 ms) but also exhibit temporal integration close to that in biological neurons. The potential of using the memristor to directly process biosensing signals is also demonstrated.

}, keywords = {Action Potentials, Biosensing Techniques, Electricity, Electronics, Equipment Design, Geobacter, Humans, Molecular Dynamics Simulation, Nanotechnology, Nanowires, Neural Networks, Computer, Neurons, Synapses, Wearable Electronic Devices}, issn = {2041-1723}, doi = {10.1038/s41467-020-15759-y}, author = {Fu, Tianda and Liu, Xiaomeng and Gao, Hongyan and Ward, Joy E and Liu, Xiaorong and Yin, Bing and Wang, Zhongrui and Zhuo, Ye and Walker, David J F and Joshua Yang, J and Chen, Jianhan and Lovley, Derek R and Yao, Jun} } @article {520, title = {Microbial fuel cells: novel microbial physiologies and engineering approaches.}, journal = {Curr Opin Biotechnol}, volume = {17}, year = {2006}, month = {2006 Jun}, pages = {327-32}, abstract = {The possibility of generating electricity with microbial fuel cells has been recognized for some time, but practical applications have been slow to develop. The recent development of a microbial fuel cell that can harvest electricity from the organic matter stored in marine sediments has demonstrated the feasibility of producing useful amounts of electricity in remote environments. Further study of these systems has led to the discovery of microorganisms that conserve energy to support their growth by completely oxidizing organic compounds to carbon dioxide with direct electron transfer to electrodes. This suggests that self-sustaining microbial fuel cells that can effectively convert a diverse range of waste organic matter or renewable biomass to electricity are feasible. Significant progress has recently been made to increase the power output of systems designed to convert organic wastes to electricity, but substantial additional optimization will be required for large-scale electricity production.}, keywords = {Bacterial Physiological Phenomena, Bioelectric Energy Sources, Biomass, Biosensing Techniques, Genetic Engineering}, issn = {0958-1669}, doi = {10.1016/j.copbio.2006.04.006}, author = {Lovley, Derek R} }