Bimodal functionality of highly conductive nanostructured silver film towards improved performance of photosystem I-based graphene photocathode

We present the novel design of photosystem I (PSI)-based biosolar cell, whereby conductive transparent electrode materials, such as ITO or FTO, are replaced with glass covered with silver island film. This nanostructured metallic layer combines high electric conductance with enhancing the absorption efficiency of the PSI biocatalyst via the plasmonic effect. We demonstrate strong enhancement of the photocurrent generated in the biohybrid electrode composed of oriented layers of PSI reaction centers due to plasmonic interactions of the PSI fluorophores and redox centres with the conductive silver island film. © 2024 The Author

Development of a Novel Nanoarchitecture of the Robust Photosystem I from a Volcanic Microalga Cyanidioschyzon merolae on Single Layer Graphene for Improved Photocurrent Generation

Here, we report the development of a novel photoactive biomolecular nanoarchitecture based on the genetically engineered extremophilic photosystem I (PSI) biophotocatalyst interfaced with a single layer graphene via pyrene-nitrilotriacetic acid self-assembled monolayer (SAM). For the oriented and stable immobilization of the PSI biophotocatalyst, an His(6)-tag was genetically engineered at the N-terminus of the stromal PsaD subunit of PSI, allowing for the preferential binding of this photoactive complex with its reducing side towards the graphene monolayer. This approach yielded a novel robust and ordered nanoarchitecture designed to generate an efficient direct electron transfer pathway between graphene, the metal redox center in the organic SAM and the photo-oxidized PSI biocatalyst. The nanosystem yielded an overall current output of 16.5 mu A center dot cm(-2) for the nickel- and 17.3 mu A center dot cm(-2) for the cobalt-based nanoassemblies, and was stable for at least 1 h of continuous standard illumination. The novel green nanosystem described in this work carries the high potential for future applications due to its robustness, highly ordered and simple architecture characterized by the high biophotocatalyst loading as well as simplicity of manufacturing.Polish National Science Center [UMO-2017/27/B/ST5/00472]M.I., M.J. and J.K. acknowledge the financial support from the Polish National Science Center (grant no. UMO-2017/27/B/ST5/00472 to J.K.)

Investigation of in vitro biological activities of hollow mesoporous carbon nanopArticles bearing D-NMAPPD on human lung adenocarcinoma cells

The uniformly dispersed hollow mesoporous carbon nanopArticles (HMCNPs) were successfully synthesized by hard-template methods, and D-NMAPPD (B13) was successfully loaded onto the nanopArticle surface for the first time. Structural properties of bare and B13 loaded HMCNPs (HMCNs-B-13) were investigated by Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission-Scanning Electron Microscopy (FE-SEM), Thermal Gravimetric Analysis (TG). The amount of drug released was determined via in vitro drug release studies at 37 degrees C in SBF through UV-Vis spectrometric and thermal analyses. TG data revealed that the proportion of loaded B-13 was 33.60%. Their ability to induce apoptosis in cultures of A549 human lung adenocarcinoma cells was investigated, and the inhibitory effect of HMCNPs-B-13 on lung cancer cell proliferation was determined in vitro. The IC50 values determined after application periods of 24 and 48 h were found to be 16.13 mu g/mL and 12.96 mu g/mL, respectively. The role of HMCNPs-B-13 on the morphology and ultrastructure of A549 cells was also investigated by confocal microscopy and Transmission electron microscopy (TEM) studies

Investigating the effect of coating and synthesis parameters on La1-xSrxMnO3 based core-shell magnetic nanoparticles

Magnetic nanoparticles are an important class of functional materials that have unique magnetic properties due to their reduced size (100 nm) and have the potential for use in many fields. In the preparation of magnetic nanoparticles, factors such as intrinsic magnetic properties, surface coating, size and shape of the particles, surface charge and stability are very important. In this regard, carefully determining the synthesis parameters of magnetic nanoparticles and particle coating materials is of critical importance in the application area chosen for the material. In this study, La1-xSrxMnO3 (x = 0.27, 0.30, 0.33) magnetic nanoparticles (MNPs), carbon-coated magnetic nanoparticles in core–shell structure (C@MNP) and their derivatives integrated into graphene oxide (GO-C@MNP) were synthesized and their properties were investigated in detail for their use in possible future application studies. The crystal structure of perovskite compounds with Pbnm symmetry remains unchanged after carbon coating but shrinks in volume due to its amorphous structure. The magnetic behavior of the uncoated and coated materials is almost identical, but the Curie temperature of the compounds shifts to a higher temperature. In the specific absorption ratio (SAR) measurements performed, it was found that the best SAR value for carbon-coated MNPs was 12.9 W/g at x = 0.27. By integrating the MNPs into graphene oxide, heat is easily distributed regionally, and this shows that the structures can be ideal candidates for applications such as hyperthermia, drug carriers, tissue repair, and cellular therapy including cell labeling and targeting. Perovskite-structured manganite materials were selected for their suitability in controlled production, where the Curie temperature can be tuned near the therapeutic temperature by adjusting the doping levels, making them ideal for magnetic hyperthermia applications. In this study, for the first time, the nanoparticle surfaces were coated with carbon, which was chosen not only due to carbon's non-magnetic nature but also because it provides an ideal platform for future combined biomedical applications such as drug delivery systems. © 2024 Elsevier B.V

Molecular mechanism of direct electron transfer in the robust cytochrome-functionalised graphene nanosystem

Construction of green nanodevices characterised by excellent long-term performance remains high priority in biotechnology and medicine. Tight electronic coupling of proteins to electrodes is essential for efficient direct electron transfer (DET) across the bio-organic interface. Rational modulation of this coupling depends on in-depth understanding of the intricate properties of interfacial DET. Here, we dissect the molecular mechanism of DET in a hybrid nanodevice in which a model electroactive protein, cytochrome c(553) (cyt c(553)), naturally interacting with photosystem I, was interfaced with single layer graphene (SLG) via the conductive self-assembled monolayer (SAM) formed by pyrene-nitrilotriacetic acid (pyr-NTA) molecules chelated to transition metal redox centers. We demonstrate that efficient DET occurs between graphene and cyt c(553) whose kinetics and directionality depends on the metal incorporated into the bio-organic interface: Co enhances the cathodic current from SLG to haem, whereas Ni exerts the opposite effect. QM/MM simulations yield the mechanistic model of interfacial DET based on either tunnelling or hopping of electrons between graphene, pyr-NTA-M2+ SAM and cyt c(553) depending on the metal in SAM. Considerably different electronic configurations were identified for the interfacial metal redox centers: a closed-shell system for Ni and a radical system for the Co with altered occupancy of HOMO/LUMO levels. The feasibility of fine-tuning the electronic properties of the bio-molecular SAM upon incorporation of various metal centers paves the way for the rational design of the optimal molecular interface between abiotic and biotic components of the viable green hybrid devices, e.g. solar cells, optoelectronic nanosystems and solar-to-fuel assemblies.Polish National Science Centre [UMO-2017/27/B/ST5/00472, UMO-2018/31/D/ST4/01475]MI, MK, MJ, SO and JK gratefully acknowledge the financial support from the Polish National Science Centre (grant no. UMO-2017/27/B/ST5/00472 to JK and UMO-2018/31/D/ST4/01475 to SO). We are grateful to Prof. Rafa Jurczakowski (CBCS ; Faculty of Chemistry, University of Warsaw, Poland) for his helpful comments on this manuscript

Enhancement of direct electron transfer in graphene bioelectrodes containing novel cytochrome c(553) variants with optimized heme orientation

The highly efficient bioelectrodes based on single layer graphene (SLG) functionalized with pyrene self-assembled monolayer and novel cytochrome c(553) (cyt c(553)) peptide linker variants were rationally designed to optimize the direct electron transfer (DET) between SLG and the heme group of cyt. Through a combination of photoelectrochemical and quantum mechanical (QM/MM) approaches we show that the specific amino acid sequence of a short peptide genetically inserted between the cyt c(553) - holoprotein and the surface anchoring C-terminal His s -tag plays a crucial role in ensuring the optimal orientation and distance of the heme group with respect to the SLG surface. Consequently, efficient DET occurring between graphene and cyt c(553) leads to a 20-fold enhancement of the cathodic photocurrent output compared to the previously reported devices of a similar type. The QM/MM modeling implies that a perpendicular or parallel orientation of the heme group with respect to the SLG surface is detrimental to DET, whereas the tilted orientation favors the cathodic photocurrent generation. Our work confirms the possibility of fine-tuning the electronic communication within complex bio-organic nanoarchitectures and interfaces due to optimization of the tilt angle of the heme group, its distance from the SLG surface and optimal HOMO/LUMO levels of the interacting redox centers. (C) 2021 The Authors. Published by Elsevier B.V.Polish National Science Center [UMO-2017/27/B/ST5/00472, UMO-2018/31/D/ST4/01475]; Center of New Technologies, University of Warsaw [501-D313-86-0119600-01]MI, MK, MJ, SO and JK gratefully acknowledge the financial support from the Polish National Science Center (grants no. UMO-2017/27/B/ST5/00472 to JK and UMO-2018/31/D/ST4/01475 to SO) . MI and SO were additionally supported by Center of New Technologies, University of Warsaw (internal grant no. 501-D313-86-0119600-01 to MI and SO)

Diazonium-Based Covalent Molecular Wiring of Single-Layer Graphene Leads to Enhanced Unidirectional Photocurrent Generation through the p-doping Effect

Development of robust and cost-effective smart materials requires rational chemical nanoengineering to provide viable technological solutions for a wide range of applications. Recently, a powerful approach based on the electrografting of diazonium salts has attracted a great deal of attention due to its numerous technological advantages. Several studies on graphene-based materials reveal that the covalent attachment of aryl groups via the above approach could lead to additional beneficial properties of this versatile material. Here, we developed the covalently linked metalorganic wires on two transparent, cheap, and conductive materials: fluorine-doped tin oxide (FTO) and FTO/single-layer graphene (FTO/SLG). The wires are terminated with nitrilotriacetic acid metal complexes, which are universal molecular anchors to immobilize His6-tagged proteins, such as biophotocatalysts and other types of redox-active proteins of great interest in biotechnology, optoelectronics, and artificial photosynthesis. We show for the first time that the covalent grafting of a diazonium salt precursor on two different electron-rich surfaces leads to the formation of the molecular wires that promote p-doping of SLG concomitantly with a significantly enhanced unidirectional cathodic photocurrent up to 1 ?A cm-2. Density functional theory modeling reveals that the exceptionally high photocurrent values are due to two distinct mechanisms of electron transfer originating from different orbitals/bands of the diazonium-derived wires depending on the nature of the chelating metal redox center. Importantly, the novel metalorganic interfaces reported here exhibit minimized back electron transfer, which is essential for the maximization of solar conversion efficiency. © 2022 American Chemical Society. All rights reserved.UMO-2017/27/B/ST5/00472, UMO-2018/31/D/ST4/01475M.J. and J.K. acknowledge the financial support from the Polish National Science Centre (OPUS14 grant no. UMO-2017/27/B/ST5/00472 to J.K.). S.O. acknowledges the financial support from the Polish National Science Centre (SONATA14 grant no. UMO-2018/31/D/ST4/01475). Computational resources were provided by the Interdisciplinary Centre for Mathematical and Computational Modeling (ICM, University of Warsaw) under the G83-28 computational grant. We are grateful to Prof. Rafa? Jurczakowski (CNBCh UW ; Faculty of Chemistry, University of Warsaw, Poland) for his insightful comments on the article and Mateusz Kasztelan (CNBCh UW and Faculty of Chemistry, University of Warsaw, Poland) for his assistance with the Raman spectroscopy measurements

Microbiota-dependent histone butyrylation in the mammalian intestine

This dataset includes supporting data for figure generation in the associated manuscript. The dataset contents include images and excel files. The image files were generated from immunoblotting (related to Figs. 1B, 2, 3E, and Extended Data Fig. 2) and immunofluorescence experiments (related to Fig. 1E). Each immunoblotting image has two files associated with each figure panel: the file name lists the figure, primary antibody, and either "ECL" = chemiluminescence only, or "full image" = chemiluminescence plus color image of entire gel, which may also include notations (such as protein ladder position or other information to orient the viewer). The excel files include quantification for figures (related to Figs. 2, 3D, Extended Data Fig. 3A), summaries of 16S sequencing results (related to Extended Data Fig. 3B), gene ontology analysis of RNA-seq data (related to Extended Data Fig. 4E) and ChIP-seq data (related to Extended Data Fig. 6), and summaries of metabolomics mass spectrometry data (related to Extended Data Fig. 5)

Evolution of the hypoxia-sensitive cells involved in amniote respiratory reflexes

textabstractThe evolutionary origins of the hypoxia-sensitive cells that trigger amniote respiratory reflexes – carotid body glomus cells, and ‘pulmonary neuroendocrine cells’ (PNECs) -are obscure. Homology has been proposed between glomus cells, which are neural crest-derived, and the hypoxia-sensitive ‘neuroepithelial cells’ (NECs) of fish gills, whose embryonic origin is unknown. NECs have also been likened to PNECs, which differentiate in situ within lung airway epithelia. Using genetic lineage-tracing and neural crest-deficient mutants in zebrafish, and physical fate-mapping in frog and lamprey, we find that NECs are not neural crest-derived, but endoderm-derived, like PNECs, whose endodermal origin we confirm. We discover neural crest-derived catecholaminergic cells associated with zebrafish pharyngeal arch blood vessels, and propose a new model for amniote hypoxia-sensitive cell evolution: endoderm-derived NECs were retained as PNECs, while the carotid body evolved via the aggregation of neural crest-derived catecholaminergic (chromaffin) cells already associated with blood vessels in anamniote pharyngeal arches