Reliable characterization techniques that guarantee real-time quality control with a non-destructive and multiscale approach are currently an essential necessity for electronic industries. Tip-Enhanced Raman Spectroscopy (TERS) offers an excellent solution to this demand. In addition to providing chemical composition through the Raman spectrometer, TERS leverages the high lateral resolution of the coupled Atomic Force Microscope, enabling chemical and morphological characterization of samples down to the nanometer scale. This study advances the application of TERS by employing ad-hoc prepared TiN-coated probes, engineered to operate in cleanrooms while guaranteeing remarkable performances in terms of electromagnetic field enhancement. The subject of this analysis is a strained-silicon-based device, a technology meant to enhance the carrier's mobility in Complementary Metal-Oxide-Semiconductor (CMOS) architectures. The goal of the characterization is to detect the strain induced by a thin Si1-xGex alloy grown on a Si(100) substrate in the silicon lattice. TERS enables not only the detection of strain in the crystal structure but also its magnitude at different levels of depth, despite the penetration depth of the laser employed. This study is a result of the activities carried out in the framework of the European Union founded project CHALLENGES included in the Horizon2020 program.

The use of engineered nanomaterials is widely distributed throughout the whole food chain to improve yield, durability, taste, and appearance of commercialized food. Moreover, nanotechnology stepped into the world of food packaging, granting better conservation of foods, avoiding bacterial contaminations, or reducing the spoiling of nutritive substances. All these improvements, however, need to be achieved in a ‘safe’ way, thus there is a wide and constantly updated legislation that deals with the possible toxicity of these additions by posing some limitation to the percentage of nanosized elements added and to their composition. Thus, the characterization of the nanomaterials ‘in situ’, e.g., directly inside the biological matrix, is of paramount importance, to measure the real concentration of the nanomaterials as well as their distribution and unwanted local modification of the biological matrix. Here we review the main high-resolution techniques that are currently used for these characterizations in combination with the most up-to-date analytical methods, i.e., X-ray (X-ray microscopy and X-ray diffraction), scanning microscopies (electron microscopy and atomic force microscopy), optical spectroscopies (infrared spectroscopy and Raman spectroscopy), and mass spectrometry, discussing their benefits and drawbacks. Some important results are reported and their applications are discussed not only in the characterization of nanosized objects deliberately added to the food and food packaging to improve their properties, but also in the characterization of unwanted nano-sized and micro-sized objects that originate from possible environmental contamination that can happen at every step of the food chain starting from water. Among them, the characterization of micro- and nano-plastics and some nanosized metallic pollutants using these analytical techniques is discussed.

Tip enhanced Raman spectroscopy (TERS) increases the spatial resolution of Raman spectroscopy to the nanoscale. The potentiality of TERS is demonstrated on single milk derived extracellular vesicles, allowing the nanoscale chemical investigation of their lipid membrane.

The semiconductor industry is undergoing a transformative phase, marked by the relentless drive for miniaturization and a constant demand for higher performance and energy efficiency. However, the reduction of metal–oxide–semiconductor field-effect transistor sizes for advanced technology nodes below 10 nm presents several challenges. In response, strained silicon technology has emerged as a key player, exploiting strain induction in the silicon crystal lattice to improve device performance. At the same time, there has been a growing need for characterization techniques that allow in-line monitoring of sample conditions during semiconductor manufacturing, as an alternative to traditional methods such as transmission electron microscopy or high-resolution X-ray diffraction, which have several limitations in terms of measurement time and sample destructiveness. This paper explores the application of advanced spectroscopic characterization techniques, in particular µ-Raman spectroscopy and tip-enhanced Raman spectroscopy (TERS), to meet the evolving needs of the semiconductor industry for quality control and failure analysis, increasingly requiring faster and non-destructive characterization techniques. µ-Raman provides insight into strain values and distributions of strained layers with different thicknesses and germanium concentrations, but its lateral resolution is constrained by the Abbe diffraction limit. TERS, on the other hand, emerges as a powerful non-destructive technique capable of overcoming diffraction limits by exploiting the combination of an atomic force microscope with a Raman spectrometer. This breakthrough makes it possible to estimate the chemical composition and induced strain in the lattice by evaluating the Raman peak position shifts in strained and unstrained silicon layers, providing crucial insights for nanoscale strain control. In particular, this paper focuses on the TERS characterization of Si 0.7 Ge 0.3 epitaxial layers grown on a silicon-on-insulator device, demonstrating the effectiveness of this technique and the high lateral resolution that can be achieved.

Carbon nanostructures are highly promising materials for applications in a variety of different fields. Besides their interesting performances, the possibility to synthesize them from biowaste makes them an eco-friendly resource widely exploitable within a circular economy context. The present work deals with the green, one-pot synthesis of graphene quantum dots (GQDs) from carbon aerogels (CAs) derived from rice husk (RH). After having obtained CAs upon purification of RH, followed by gelification and carbonization of the resulting cellulose, the one-pot solventless production of GQDs was obtained by ball milling. This method determined the formation of crystalline nanostructures with a diameter of around 20 nm, which were analyzed via scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Raman spectroscopy to obtain a full morphological and structural characterization. GQDs were used as electrode materials for supercapacitors and Li-ion batteries, showing the ability to both accumulate charges over the surface and intercalate lithium-ions. The reported results are a proof of principle of the possibility of exploiting GQDs as support material for the development of advanced systems for energy storage.

Aims Hypogeal environments with cultural heritage interest pose a real challenge for their preservation and conservation. The ancient Etruscan Necropolis of Tarquinia, Italy, consists of 200 tombs decorated with extraordinary mural paintings, of great artistic and historical value. Since the beginning of the restoration campaign in 2016, a regular microbiological survey has been performed in the Tomba degli Scudi. The aim of this study was to investigate the nature of an expansion of black spots on the pictorial layers recently observed.Methods and results To determine the origin of the black spots in the atrium chamber of the Tomba degli Scudi, the fungal community was sampled using various techniques: cellulose discs, swabs, and nylon membranes and investigated by a multi-analytical approach. The obtained results suggest that the identified fungal strains (e.g. Gliomastix murorum and Pseudogymnoascus pannorum) are common to many subterranean environments around the world, such as Lascaux cave.Conclusions The continuous and long-term monitoring made it possible to detect alterations at an early stage and assess the harmfulness of different fungal strains. This work is a demonstration of the effectiveness of prevention and monitoring actions within these fragile and valuable environments.

An integrated approach combining thermal and electrochemical technologies for the valorization of agro-industrial waste. The resulting carbon dots (CDs) show fascinating optical properties, enabling their application as fluorescent chemical probes.

Correlative microscopy stands out for its ability to concurrently acquire and analyze various data types in a multimodal and multiscale environment, enabling precise localization of specific areas within samples and enhancing the accuracy and relevance of analyses. This approach showed promise in revealing the metallurgical history of ancient coins. This article focused on composition, microstructure, and manufacturing process of Phoenician-Punic copper-based alloy coins (5th-4th century BCE). The four coins studied by correlative light and electron microscopy, mu-Raman spectroscopy, and X-ray Microscopy exhibited notable differences in elemental composition and microstructures. These variations are attributed to their origin from casting, followed by striking, and subsequent recrystallization due to a more intricate corrosion process.

In recent years, Electrospinning (ES) has been revealed to be a straightforward and innovative approach to manufacture functionalized nanofiber-based membranes with high filtering performance against fine Particulate Matter (PM) and proper bioactive properties. These qualities are useful for tackling current issues from bacterial contamination on Personal Protective Equipment (PPE) surfaces to the reusability of both disposable single-use face masks and respirator filters. Despite the fact that the conventional ES process can be upscaled to promote a high-rate nanofiber production, the number of research works on the design of hybrid materials embedded in electrospun membranes for face mask application is still low and has mainly been carried out at the laboratory scale. In this work, a multi-needle ES was employed in a continuous processing for the manufacturing of both pristine Poly (Vinylidene Fluoride-co-Hexafluoropropylene) (PVDF-HFP) nanofibers and functionalized membrane ones embedded with TiO2 Nanoparticles (NPs) (PVDF-HFP@TiO2). The nanofibers were collected on Polyethylene Terephthalate (PET) nonwoven spunbond fabric and characterized by using Scanning Electron Microscopy and Energy Dispersive X-ray (SEM-EDX), Raman spectroscopy, and Atomic Force Microscopy (AFM) analysis. The photocatalytic study performed on the electrospun membranes proved that the PVDF-HFP@TiO2 nanofibers provide a significant antibacterial activity for both Staphylococcus aureus (~94%) and Pseudomonas aeruginosa (~85%), after only 5 min of exposure to a UV-A light source. In addition, the PVDF-HFP@TiO2 nanofibers exhibit high filtration efficiency against submicron particles (~99%) and a low pressure drop (~3 mbar), in accordance with the standard required for Filtering Face Piece masks (FFPs). Therefore, these results aim to provide a real perspective on producing electrospun polymer-based nanotextiles with self-sterilizing properties for the implementation of advanced face masks on a large scale.

3D imaging is a powerful tool of high resolution and non-destructive imaging technology for the study of ancient weapons and military technology, which reveals the original microstructures and corrosion patterns that threaten these artefacts. Here we report quantitative analysis of the 3D distribution and the orientation of fractures, and uncorroded metal particles within a wrought iron javelin unearthed at the Phoenician-Punic site of Motya, Italy. The study aimed to gain a better understanding of the relationship between corrosion and local stresses within the artifact and to evaluate its manufacturing technology, as well as the effects of post-treatment with Paraloid B72 on concretion and mineralized layers. The cracks were quantified in terms of content, size, and orientation. The condition of artefact storage was evaluated by a multi-analytical approach, including X-ray microscopy, field emission electron microscopy and micro-Raman spectroscopy. The results indicated that a specific technique was used to create a sturdy, lightweight javelin with a central shaft for piercing or thrusting. The fractures appear elongated in the direction of the longitudinal axis of the blade, showing the forging direction of the original metallic block. The study concluded that the artifact had not yet been stabilized due to the presence of lepidocrocite.

The management of the Museo Territoriale del Lago di Bolsena has made various types of archaeological finds available for non-destructive and non-invasive analysis using advanced techniques.The finds date from the Roman period and were collected during the excavation campaigns of the French School in the archaeological area of Poggio Moscini in the town of Bolsena (Viterbo) between 1962 and 1973.The finds on which the analyses focused are: metallic handles, pots and mosaic tiles.The techniques used to carry out this archaeometric study are based on X-ray diffraction (XRD).In addition, Raman and Fourier-Transform IR (FTIR) spectroscopies in the reflection mode have been considered for the characterisation of the finds.The content of this paper is part of the research activity of the project REMEDIAVI (Ricostruzione virtuale ed in realtà aumentata di Volsinii Novi: un approccio avanzato per la fruibilità sostenibile dell'area archeologica di Bolsena).