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.

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.

We introduce a new scanning probe microscopy (SPM) concept called reverse tip sample scanning probe microscopy (RTS SPM), where the tip and sample positions are reversed as compared to traditional SPM. The main benefit of RTS SPM over the standard SPM configuration is that it allows for simple and fast tip changes. This overcomes two major limitations of SPM which are slow data acquisition and a strong dependency of the data on the tip condition. A probe chip with thousands of sharp integrated tips is the basis of our concept. We have developed a nanofabrication protocol for Si based probe chips and their functionalization with metal and diamond coatings, evaluated our probe chips for various RTS SPM applications (multi-tip imaging, SPM tomography, and correlative SPM), and showed the high potential of the RTS SPM concept.

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 Si_1‐xGe_x 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.