Recent Developments in Atomic Force Microscopy and Raman Spectroscopy for Materials Characterization

This book contains chapters that describe advanced atomic force microscopy (AFM) modes and Raman spectroscopy. It also provides an in-depth understanding of advanced AFM modes and Raman spectroscopy for characterizing various materials. This volume is a useful resource for a wide range of readers, including scientists, engineers, graduate students, postdoctoral fellows, and scientific professionals working in specialized fields such as AFM, photovoltaics, 2D materials, carbon nanotubes, nanomaterials, and Raman spectroscopy

Advanced 1D heterostructures based on nanotube templates and molecules

Recent advancements in materials science have shed light on the potential of exploring hierarchical assemblies of molecules on surfaces, driven by both fundamental and applicative challenges. This field encompasses diverse areas including molecular storage, drug delivery, catalysis, and nanoscale chemical reactions. In this context, the utilization of nanotube templates (NTs) has emerged as promising platforms for achieving advanced one-dimensional (1D) molecular assemblies. NTs offer cylindrical, crystalline structures with high aspect ratios, capable of hosting molecules both externally and internally (Mol@NT). Furthermore, NTs possess a wide array of available diameters, providing tunability for tailored assembly. This review underscores recent breakthroughs in the field of Mol@NT. The first part focuses on the diverse panorama of structural properties in Mol@NT synthesized in the last decade. The advances in understanding encapsulation, adsorption, and ordering mechanisms are detailed. In a second part, the review highlights the physical interactions and photophysics properties of Mol@NT obtained by the confinement of molecules and nanotubes in the van der Waals distance regime. The last part of the review describes potential applicative fields of these 1D heterostructures, providing specific examples in photovoltaics, luminescent materials, and bio-imaging. A conclusion gathers current challenges and perspectives of the field to foster discussion in related communities

Advanced 1D heterostructures based on nanotube templates and molecules

Recent advancements in materials science have shed light on the potential of exploring hierarchical assemblies of molecules on surfaces, driven by both fundamental and applicative challenges. This field encompasses diverse areas including molecular storage, drug delivery, catalysis, and nanoscale chemical reactions. In this context, the utilization of nanotube templates (NTs) has emerged as promising platforms for achieving advanced one-dimensional (1D) molecular assemblies. NTs offer cylindrical, crystalline structures with high aspect ratios, capable of hosting molecules both externally and internally (Mol@NT). Furthermore, NTs possess a wide array of available diameters, providing tunability for tailored assembly. This review underscores recent breakthroughs in the field of Mol@NT. The first part focuses on the diverse panorama of structural properties in Mol@NT synthesized in the last decade. The advances in understanding encapsulation, adsorption, and ordering mechanisms are detailed. In a second part, the review highlights the physical interactions and photophysics properties of Mol@NT obtained by the confinement of molecules and nanotubes in the van der Waals distance regime. The last part of the review describes potential applicative fields of these 1D heterostructures, providing specific examples in photovoltaics, luminescent materials, and bio-imaging. A conclusion gathers current challenges and perspectives of the field to foster discussion in related communities

THE SELECTION OF HIGHLY STABLE APTAMERS FROM A 2’-FULLY MODIFIED fGmH RNA LIBRARY

When developed as tools for applications within biological systems, RNA aptamers immediately face numerous obstacles, in particular nuclease degradation and post-selection 2’ modification. This study aimed to develop a novel class of highly stable, 2’-fully modified RNA aptamers directly selectable from a fGmH RNA library with improved nuclease stability. The facile transcription of a fGmH (2’-F-dG, 2’-OMe-dA/dC/dU) RNA library was performed, from which aptamers were directly selected that bind Staphylococcus aureus Protein A (SpA). The superior nuclease and serum stability of these fGmH aptamers was demonstrated in comparison to 2’-partially modified RNA variants. Characterizations of fGmH RNA aptamers binding to purified SpA and to endogenous SpA present on the surface of S. aureus cells demonstrated fGmH RNA aptamer selectivity and stability. Significantly, fGmH RNA aptamers were able to functionalize, stabilize, and specifically deliver aggregation-prone silver nanoparticles (AgNPs) to S. aureus with SpA-dependent antimicrobial effects. Attempted selection of fGmH RNA aptamers against other targets, namely the PD-1 immune checkpoint, led to the selection of a single non-binding sequence during the selection against PD-1, as well as several non-binding sequence motif groups during the selection against PD-L1. Overall, this dissertation demonstrates the selection and deployment of Protein A binding fGmH RNA aptamers against S. aureus, discusses hypotheses and results aimed at explaining the selection of PD-1 and PD-L1 non-binding sequences, and describes a novel aptamer class with considerable potential to improve the in vivo applicability of nucleic acid-based affinity molecules.Doctor of Philosoph

Recent Advances in the Use of Ionic Liquids and Deep Eutectic Solvents for Lignocellulosic Biorefineries and Biobased Chemical and Material Production

Biorefineries, which process biomass feedstocks into valuable (bio)products, aim to replace fossil fuel-based refineries to produce energy and chemicals, reducing environmental and health hazards, including climate change, and supporting a sustainable economy. In particular, lignocellulose-based biorefineries, utilizing the most abundant renewable feedstock on Earth, have significant potential to supply sustainable energy, chemicals and materials. Ionic liquids (ILs, organic salts with low melting temperatures) and deep eutectic solvents (DESs, mixtures with eutectic points lower than the ideal mixture) are capable of dissolving some of the key lignocellulose polymers, and even the whole biomass. Furthermore, they have intrinsic advantages over molecular solvents, including safer usage profiles and high tunability, which allow tailored physicochemical properties. Such properties provide unique opportunities for the development of new processes that could unlock the full potential of future biorefineries. Here, we review the current state of lignocellulosic biomass processing with ILs and DESs, with a specific focus on the pretreatment chemistry, process flow and products from each component; followed by discussions on sustainability assessments and technological challenges. We aim to inform the research community about the opportunities, challenges and perspectives in developing truly sustainable lignocellulose-based biorefineries

Valorisation of unconventional lignocellulosic biomass into bioenergy and bioproducts using ionic-liquid based technologies

In order to transition energy use away from fossil fuels, the transformation of renewable lignocellulosic biomass needs to be improved and its supply of sustainable bioenergy into a wider bioeconomy increased. Achieving this will require: (1) renewable, cheap and high-quality lignocellulosic feedstocks, (2) a robust process to transform this feedstock into bioenergy and finally (3) a system to recover and use this bioenergy as well as value-added products. In this PhD, multiple examples were used to explore unconventional feedstocks, novel transformation processes and opportunities for value-added products. Feedstocks ranging from invasive species threatening the UK environment, Rhododendron and Japanese Knotweed (Chapter 3), metal contaminated waste wood (Chapter 4), metal enriched biomass grown on marginal land (Chapter 5), and wastewater irrigated willow, a leading dedicated bioenergy crop (Chapter 6). While conventional bioenergy systems often burn wood pellets for energy co-generation, the innovative transformation process of ionic liquid-based technologies are explored as flexible enough to fractionate unconventional biomass feedstocks and deliver high yields of sustainable bioenergy and bioproducts. This was allowed by the unique and tuneable properties of protic ionic liquids. Here dimethylbutyl-hydrogen sulphate - [DMBA][HSO4], a cheap hydrogen sulphate [HSO4]- based ionic liquid, and 1-methylimidazolium chloride - [C1Him][Cl], were used in the ionic-liquid based ionoSolv process. Key efficiency parameters such as temperature, reaction time, biomass to solvent loading and solvent recycling, were explored. The process was also challenged with the presence of diverse metal contamination to determine the potential to extract the metals and produce a fermentable pulp and lignin in parallel. Bioenergy recovery from the ionoSolv process was explored as well as the potential to recover multiple value-added products. In addition to determination of heating values of isolated lignin as well as hydrolysis and fermentation yields of cellulose rich pulps into bioethanol, interactions of contaminating metals and their impact on yeast fermentation yields were investigated. This investigation highlights the benefits of [C1Him][Cl] ionic liquid pretreatment for the production of clean bioenergy and bioproducts from highly contaminated feedstocks. As an important property of ionic liquids is that they can act as media for electrochemical reactions, electrodeposition of metals from ionic liquid liquor, metal extraction efficiencies and any detrimental interactions with ionic liquid recycling were assessed. To further diversify system outputs beyond bioenergy alone, production of bio-oils, char and gases from pyrolysis of post-hydrolysis residue was determined, as well as the possibility for recovery of phytochemicals as potential complementary value-added products. This research highlights that unconventional feedstocks have the potential to support a developing bioeconomy and that the reallocation of waste and reclamation of contaminated soils and waters could act as a financial, social and environmental levers to improve the sustainability of bioenergy production. The studies also showcase how a versatile engineered ionic-liquid pretreatment has the potential to transform environmental burdens into resources that are compatible with the diversification of multiple product streams. Taken together, these findings can serve as a proof-of-concept for integrated scale-up of sustainable ionic-liquid based biorefinery.Open Acces

Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity

Gold nanoparticles (Au NPs) have received great attention owing to their biocompatible nature, environmental, and widespread biomedical applications. Au NPs are known as capable to regulate inflammatory responses in several tissues and organs; interestingly, lower toxicity in conjunction with anti-inflammatory effects was reported to occur with Au NPs treatment. Several variables drive this benefit-risk balance, including Au NPs physicochemical properties such as their morphology, surface chemistry, and charge. In our research we prepared hybrid Au@LCC nanocolloids by the Pulsed Laser Ablation, which emerged as a suitable chemically clean technique to produce ligand-free or functionalized nanomaterials, with tight control on their properties (product purity, crystal structure selectivity, particle size distribution). Here, for the first time to our knowledge, we have investigated the bioproperties of Au@LCCs. When tested in vitro on intestinal epithelial cells exposed to TNF-α, Au@LCCs sample at the ratio of 2.6:1 showed a significantly reduced TNF gene expression and induced antioxidant heme oxygenase-1 gene expression better than the 1:1 dispersion. Although deeper investigations are needed, these findings indicate that the functionalization with LCCs allows a better interaction of Au NPs with targets involved in the cell redox status and inflammatory signaling.</jats:p

Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity

Gold nanoparticles (Au NPs) have received great attention owing to their biocompatible nature, environmental, and widespread biomedical applications. Au NPs are known as capable to regulate inflammatory responses in several tissues and organs; interestingly, lower toxicity in conjunction with anti-inflammatory effects was reported to occur with Au NPs treatment. Several variables drive this benefit-risk balance, including Au NPs physicochemical properties such as their morphology, surface chemistry, and charge. In our research we prepared hybrid Au@LCC nanocolloids by the Pulsed Laser Ablation, which emerged as a suitable chemically clean technique to produce ligand-free or functionalized nanomaterials, with tight control on their properties (product purity, crystal structure selectivity, particle size distribution). Here, for the first time to our knowledge, we have investigated the bioproperties of Au@LCCs. When tested in vitro on intestinal epithelial cells exposed to TNF-α, Au@LCCs sample at the ratio of 2.6:1 showed a significantly reduced TNF gene expression and induced antioxidant heme oxygenase-1 gene expression better than the 1:1 dispersion. Although deeper investigations are needed, these findings indicate that the functionalization with LCCs allows a better interaction of Au NPs with targets involved in the cell redox status and inflammatory signaling