Mon 13 May 14:30: "Hops, Walks, and Spins: The Choreography of Cellular Electron Transport at Biotic-Abiotic Interfaces"
Electronic components that bridge the biotic-abiotic interface will have vast implications for both studying and harnessing the activity of living cells. While much ongoing research focuses on applying traditional rigid electronics to biology, an alternative is to discover bioelectronic solutions that life itself evolved to interact with the abiotic world. Towards realizing this vision, recent studies at the interface of microbiology, electrochemistry, and physics have uncovered metalloprotein electron conduits and nanowires that electronically link bacteria to extracellular surfaces ranging from environmental minerals to solid-state electrodes. Since this extracellular electron transport naturally evolved to interact with external surfaces, a fundamental understanding has special implications for new bioelectrochemical technologies and living electronics that harness the advantages of microbes in detecting external signals or hosting synthetic genetic circuits.
We will describe our recent progress in understanding extracellular and intercellular electron transport at multiple length scales, from the biophysics of individual multiheme cytochromes to the electrophysiology of whole bacteria and multicellular communities ranging from biofilms to cable bacteria. Using electrochemistry, single molecule tracking, stochastic simulations of cell surface multiheme cytochromes, and lithographic patterning of electrode attached biofilms, we describe how the interplay of cytochrome dynamics and electron hopping can give rise to long-distance electron conduction along bacterial membrane surfaces. In addition, we describe strategies to characterize and harness the electrochemical activity, spin filtering, and conduction properties of bacterial electron conduits in both synthetic structures and living biofilms.
This talk will be highly interdisciplinary and aimed at a broad audience (chemistry, biochemistry, biophysics, and microbiology).
There are limited slots available for meeting & chatting with the presenter, there is also the opportunity to meet over lunch or dinner. Please email ASAP j.zhang.group.admin@ch.cam.ac.uk (Alexandra Campbell) with your contact details and preferred option if you would like to take up this opportunity. Postgraduates, PDR As and PIs are all welcome to take up this offer.
- Speaker: Professor Moh El-Naggar, Departments of Physics, Biological Sciences, and Chemistry, University of Southern California, USA
- Monday 13 May 2024, 14:30-15:30
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Wed 24 Apr 14:15: Porphyrins In Discrete Metal-Mediated Assemblies
Given the fundamental role of (metallo)porphyrins in various natural processes, integration of these functional units into artificial ensembles is an enduring task for supramolecular chemists.1a,b In this wide context, the metal-mediated assembling approach has afforded a variety of spectacular 3D discrete arrays of porphyrins with new functions, ranging from molecular recognition to (photo)catalysis.1c Over the years we also have employed (metallo)porphyrins and coordination compounds for the obtainment of discrete multi-component systems, mostly for artificial photosynthesis purposes.2 More recently, we expanded our interests towards two main directions: i. preparation and photophysical investigation of metalloporphyrins as photosensitizers/catalysts for H2 generation3a or as photoactive units to model Proton Coupled Electron Transfer processes;3b,c ii. possible strategies for the obtainment of heretoleptic porphyrin metallacycles.4 An excursion on the most fascinating past and recent examples will be presented. References 1. a) C.M. Drain, A. Varotto, I. Radivojevic, Chem. Rev. 2009, 109, 1630; b) S. Durot, J. Taesch, V. Heitz, Chem. Rev. 2014, 114, 8542; c) E.G. Percástegui, V. Jancik, Coord. Chem. Rev. 2020, 407, 213165. 2. a) M. Marchini, A. Luisa, G. Bergamini, N. Armaroli, B. Ventura, M. Baroncini, N. Demitri, E. Iengo, P. Ceroni, Chem. Eur. J. 2021, 27, 1625; b) A. Amati, G. Cecot, I. Regeni, E. Giraldi, N. Demitri, K. Severin, E. Iengo, manuscript in preparation. 3. a) refs in: K. Ladomenou, M. Natali, E. Iengo, G. Charalampidis, F. Scandola, A. G. Coutsolelos, Coord. Chem. Rev. 2015, 304-305, 38; b) M. Natali, A. Amati, N. Demitri, E. Iengo, Chem. Commun. 2018, 54, 6148; c) M. Natali, A. Amati, N. Demitri, E. Iengo, Chem. Eur. J. 2021, 27, 7872. 4. a) A. Vidal, F. Battistin, G. Balducci, E. Iengo, E. Alessio, Inorg. Chem. 2021, 60, 11503; b) A. Vidal, D. Rossato, E. Iengo, G. Balducci, E. Alessio, Chem. Eur. J. 2023, doi.org/10.1002/chem.202300893; c) S. Simonato, C. Mucignato, G. Fogar, E. Zangrando, G. Balducci, E. Iengo, unpublished results.
- Speaker: Professor Elisabetta Iengo
- Wednesday 24 April 2024, 14:15-15:15
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Wed 24 Apr 14:15: Porphyrins In Discrete Metal-Mediated Assemblies
Given the fundamental role of (metallo)porphyrins in various natural processes, integration of these functional units into artificial ensembles is an enduring task for supramolecular chemists.1a,b In this wide context, the metal-mediated assembling approach has afforded a variety of spectacular 3D discrete arrays of porphyrins with new functions, ranging from molecular recognition to (photo)catalysis.1c Over the years we also have employed (metallo)porphyrins and coordination compounds for the obtainment of discrete multi-component systems, mostly for artificial photosynthesis purposes.2 More recently, we expanded our interests towards two main directions: i. preparation and photophysical investigation of metalloporphyrins as photosensitizers/catalysts for H2 generation3a or as photoactive units to model Proton Coupled Electron Transfer processes;3b,c ii. possible strategies for the obtainment of heretoleptic porphyrin metallacycles.4 An excursion on the most fascinating past and recent examples will be presented.
- Speaker: Professor Elisabetta Iengo
- Wednesday 24 April 2024, 14:15-15:15
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Thu 14 Mar 14:00: Organic Nanoionics in Polymers for Energy Conversion System
Nanoionics is known as unique phenomena and properties connected with fast ion transport in all-solid-state nanoscale systems, especially in inorganic materials. We first revealed similar fast ion transport in organic polymer nanofibers fabricated by electrospinning and named this phenomenon “Organic Nanoionics” [1]. First, I will present such unique proton, anion, and lithium ion transport properties in the electrospun polymer nanofibers [2,3]. Then, I will share our work on polymer electrolyte membranes for fuel cells and secondary batteries [4-6]. The ion conductive polymer nanofiber composite electrolyte membranes showed improved electrolyte characteristics and fuel cell/battery performances by utilizing fast ion transport properties based on organic nanoionics. Finally, our recent work on hydrogen production by anion exchange membrane water electrolysis will be also presented [7].
[1] M. Tanaka, Polymer Journal, 48, 51 (2016). [2] R. Takemori, M. Tanaka, et al., RSC Advances, 4, 20005 (2014). [3] T. Watanabe, M. Tanaka, et al., Nanoscale, 8, 19614 (2016). [4] M. Tanaka, et al., “Electrospun Sulfonated Polyimide Nanofibers for Polymer Electrolyte Composite Membranes”, in “Polyimides – Advances in Blends and Nanocomposites”, M.-D. Damaceanu, R. N. Darie-Nita, Eds, Chapter 9, pp325-352, Elsevier (2023). [5] M. Tanaka et al., Journal of Power Sources, 342, 125 (2017). [6] T. Watanabe, M. Tanaka, et al., Journal of Power Sources, 423, 255 (2019). [7] Y. Nara, M. Tanaka, et al., Polymers for Advanced Technology, 33, 2863 (2022).
- Speaker: Prof. Manabu Tanaka, Tokyo Metropolitan University
- Thursday 14 March 2024, 14:00-15:00
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Thu 07 Mar 14:00: Formulating protein behaviour in nanospace: Key to rational glue screening
Understanding the interactions among biomolecules, such as proteins and nucleic acids, is fundamental to life’s processes and remains a central focus of biochemistry and molecular biology. To advance this understanding, researchers mix relevant molecules in controlled extracellular settings, a method crucial for detailed examination of molecular interactions and a key technique in field evolution. The theoretical bedrock of these experiments is chemical and enzyme kinetics, established over a century ago. Given its robustness and broad applicability, the theory has remained unaltered to this day. Yet, with the advent of modern techniques for molecular manipulation and observation, once beyond the theory’s foresight, there is now a significant opportunity to extend the theory, facilitating new experimental designs. Here, we revisit and expand the principles of chemical and enzyme kinetics to encompass a broader range of phenomena, proposing an experimental setup that more closely mirrors intracellular conditions. At first glance, the proposed experimental system, which deals with particles confined within nanospaces, might appear peculiar and unnatural; however, theoretical insights have demonstrated its closer alignment with ‘natural’ processes, defying initial assumptions. Illustratively, this approach has allowed for a fundamental derivation of Michaelis-Menten equation, a cornerstone formula in the field. We showcase its practical utility through the successful screening of molecular glues, a task previously considered lacking a rational methodology. Our theoretical framework does not merely open new experimental doors; it also provides a profound yet straightforward answer to the perennial question of why simple mixing of constituents in a test tube does not recreate life. Also, it introduces measures for previously ambiguous concepts such as ‘local concentration’ in molecular interactions and ‘artifacts’ in biomolecular modifications, offering a foundation for the quantitative analysis of these critical notions for the first time. The introduction of these measures promises to deepen our comprehension of molecular phenomena within cells.
- Speaker: Prof. Daishi Fujita, Kyoto University iCeMS Institute for Integrated Cell-Material Sciences
- Thursday 07 March 2024, 14:00-15:00
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Thu 07 Mar 14:00: Organic Nanoionics in Polymers for Energy Conversion System
Nanoionics is known as unique phenomena and properties connected with fast ion transport in all-solid-state nanoscale systems, especially in inorganic materials. We first revealed similar fast ion transport in organic polymer nanofibers fabricated by electrospinning and named this phenomenon “Organic Nanoionics” [1]. First, I will present such unique proton, anion, and lithium ion transport properties in the electrospun polymer nanofibers [2,3]. Then, I will share our work on polymer electrolyte membranes for fuel cells and secondary batteries [4-6]. The ion conductive polymer nanofiber composite electrolyte membranes showed improved electrolyte characteristics and fuel cell/battery performances by utilizing fast ion transport properties based on organic nanoionics. Finally, our recent work on hydrogen production by anion exchange membrane water electrolysis will be also presented [7].
[1] M. Tanaka, Polymer Journal, 48, 51 (2016). [2] R. Takemori, M. Tanaka, et al., RSC Advances, 4, 20005 (2014). [3] T. Watanabe, M. Tanaka, et al., Nanoscale, 8, 19614 (2016). [4] M. Tanaka, et al., “Electrospun Sulfonated Polyimide Nanofibers for Polymer Electrolyte Composite Membranes”, in “Polyimides – Advances in Blends and Nanocomposites”, M.-D. Damaceanu, R. N. Darie-Nita, Eds, Chapter 9, pp325-352, Elsevier (2023). [5] M. Tanaka et al., Journal of Power Sources, 342, 125 (2017). [6] T. Watanabe, M. Tanaka, et al., Journal of Power Sources, 423, 255 (2019). [7] Y. Nara, M. Tanaka, et al., Polymers for Advanced Technology, 33, 2863 (2022).
- Speaker: Prof. Manabu Tanaka, Tokyo Metropolitan University
- Thursday 07 March 2024, 14:00-15:00
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Thu 07 Mar 14:00: Formulating protein behaviour in nanospace: Key to rational glue screening
of these experiments is chemical and enzyme kinetics, established over a century ago. Given its robustness and broad applicability, the theory has remained unaltered to this day. Yet, with the advent of modern techniques for molecular manipulation and observation, once beyond the theory’s foresight, there is now a significant opportunity to extend the theory, facilitating new experimental designs. Here, we revisit and expand the principles of chemical and enzyme kinetics to encompass a broader range of phenomena, proposing an experimental setup that more closely mirrors intracellular conditions. At first glance, the proposed experimental system, which deals with particles confined within nanospaces, might appear peculiar and unnatural; however, theoretical insights have demonstrated its closer alignment with ‘natural’ processes, defying initial assumptions. Illustratively, this approach has allowed for a fundamental derivation of Michaelis-Menten equation, a cornerstone formula in the field. We showcase its practical utility through the successful screening of molecular glues, a task previously considered lacking a rational methodology. Our theoretical framework does not merely open new experimental doors; it also provides a profound yet straightforward answer to the perennial question of why simple mixing of constituents in a test tube does not recreate life. Also, it introduces measures for previously ambiguous concepts such as ‘local concentration’ in molecular interactions and ‘artifacts’ in biomolecular modifications, offering a foundation for the quantitative analysis of these critical notions for the first time. The introduction of these measures promises to deepen our comprehension of molecular phenomena within cells.
- Speaker: Prof. Daishi Fujita, Kyoto University iCeMS Institute for Integrated Cell-Material Sciences
- Thursday 07 March 2024, 14:00-15:00
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Thu 07 Mar 14:00: Organic Nanoionics in Polymers for Energy Conversion System
tbc
- Speaker: Prof. Manabu Tanaka, Tokyo Metropolitan University
- Thursday 07 March 2024, 14:00-15:00
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.
Thu 07 Mar 14:00: Prof. Daishi Fujita, Kyoto University iCeMS
tbc
- Speaker: Prof. Daishi Fujita, Kyoto University iCeMS Institute for Integrated Cell-Material Sciences
- Thursday 07 March 2024, 14:00-15:00
- Venue: Dept. of Chemistry, Pfizer Lecture Theater.
- Series: Materials Chemistry Research Interest Group; organiser: Sharon Connor.