Alkoxysilane-Mediated Decoration of Si Nanowires Vertical Arrays with Au Nanoparticles as Improved SERS-Active Platforms.

The search for improved transducers to fabricate better-performing (bio)sensors is a challenging but rewarding endeavor aiming to better diagnose and treat diseases. In this paper, we report on the decoration of a dense vertical array of ultrathin silicon nanowires (Si NWs), produced by metal-assisted chemical etching, with 20 nm gold nanoparticles (Au NPs) for surface-enhanced Raman scattering (SERS) applications. To optimize the production of a uniform 3D SERS active platform, we tested different Si NW surface functionalizations with various alkoxysilanes before Au decoration. Scanning electron microscopy investigations confirm that Au NPs decorate both bare and (3-glycidiloxypropyl)trimethoxysilane (GPTMS)-modified Si NWs with a high surface coverage uniformity. The SERS response of the decorated NWs was probed using a model dye system (methylene blue; MB) at 633 and 785 nm excitation wavelengths. The GPTMS-modified NWs present the highest enhancements of 2.9 and 2.6 for the 450 cm-1 and 1625 cm-1 peaks under 785 nm excitation and of 10.8 and 5.3 for the 450 cm-1 and 1625 cm-1 peaks under 633 nm excitation. These results demonstrate the perspective role of Si NWs decorated with Au NPs as a low-cost 3D SERS platform.

Luminescent Silicon Nanowires as Novel Sensor for Environmental Air Quality Control.

Air quality monitoring is an increasingly debated topic nowadays. The increasing spillage of waste products released into the environment has contributed to the increase in air pollution. Consequently, the production of increasingly performing devices in air monitoring is increasingly in demand. In this scenario, the attention dedicated to workplace safety monitoring has led to the developing and improving of new sensors. Despite technological advancements, sensors based on nanostructured materials are difficult to introduce into the manufacturing flow due to the high costs of the processes and the approaches that are incompatible with the microelectronics industry. The synthesis of a low-cost ultra-thin silicon nanowires (Si NWs)-based sensor is here reported, which allows us the detection of various dangerous gases such as acetone, ethanol, and the ammonia test as a proof of concept in a nitrogen-based mixture. A modified metal-assisted chemical etching (MACE) approach enables to obtain ultra-thin Si NWs by a cost-effective, rapid and industrially compatible process that exhibit an intense light emission at room temperature. All these gases are common substances that we find not only in research or industrial laboratories, but also in our daily life and can pose a serious danger to health, even at small concentrations of a few ppm. The exploitation of the Si NWs optical and electrical properties for the detection of low concentrations of these gases through their photoluminescence and resistance changes will be shown in a nitrogen-based gas mixture. These sensing platforms give fast and reversible responses with both optical and electrical transductions. These high performances and the scalable synthesis of Si NWs could pave the way for market-competitive sensors for ambient air quality monitoring.

Hybrid Platforms of Silicon Nanowires and Carbon Nanotubes in an Ionic Liquid Bucky Gel.

Silicon nanowires (NWs) are appealing building blocks for low-cost novel concept devices with improved performances. In this research paper, we realized a hybrid platform combining an array of vertically oriented Si NWs with different types of bucky gels, obtained from carbon nanotubes (CNT) dispersed into an ionic liquid (IL) matrix. Three types of CNT bucky gels were obtained from imidazolium-based ionic liquids (BMIM-I, BIMI-BF4, and BMIM-Tf2N) and semiconductive CNTs, whose structural and optical responses to the hybrid platforms were analyzed and compared. We investigated the electrical response of the IL-CNT/NW hybrid junctions in dark and under illumination for each platform and its correlation to the ionic liquid characteristics and charge mobility. The reported results confirm the attractiveness of such IL-CNT/NW hybrid platforms as novel light-responsive materials for photovoltaic applications. In particular, our best performing cell reported a short-circuit current density of 5.6 mA/cm2 and an open-circuit voltage of 0.53 V.

Decoration of silicon nanowires with silver nanoparticles for ultrasensitive surface enhanced Raman scattering.

Silicon nanowires (Si NWs), produced by the chemical etching technique, were decorated with silver nanoparticles (NPs) produced at room temperature by the pulsed laser deposition (PLD) technique. Silver NPs were obtained by means of nanosecond pulsed laser ablation of a target in the presence of a controlled Ar atmosphere. Two different laser pulse numbers and Si NWs having different lengths were used to change the NP number density on the Si NW surface. The resulting Ag NP morphologies were studied by scanning electron microscopy imaging. The results show that this industrially compatible technological approach allows the coverage of the Si NW walls with Ag NPs with a strong control of the NP size distribution and spatial arrangement. The obtained Ag NP decorated Si NWs are free from chemicals contamination and there is no need of post deposition high temperature processes. The optical properties of Si NW arrays were investigated by reflectance spectroscopy that showed the presence of a plasmon related absorption peak, whose position and width is dependent on the Ag NP surface morphology. Coupling the huge surface-to-volume ratio of Si NW arrays with the plasmonic properties of silver nanoparticles resulted in a 3D structure suitable for very sensitive surface enhanced Raman scattering (SERS) applications, as demonstrated by the detection of Rhodamine 6G in aqueous solution at a concentration level of 10(-8) M.

Biotinylated polyaminoacid-based nanoparticles for the targeted delivery of lenvatinib towards hepatocarcinoma.

In this work, we describe the development of targeted polymeric nanoparticles loaded with lenvatinib for the treatment of hepatocellular carcinoma (HCC). A synthetic brush copolymer (PHEA-g-BIB-pButMA-g-PEG-biotin) was synthesized from α-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) by a three-step reaction involving atom transfer radical polymerisation (ATRP) to graft hydrophobic polybutylmethacrylate pendant groups and further conjugation with biotinylated polyethylene glycol via carbonate ester. Subsequently, lenvatinib-loaded nanoparticles were obtained and characterized demonstrating colloidal size, negative zeta potential, biotin exposure on the surface and the ability to release lenvatinib in a sustained manner. Lenvatinib-loaded nanoparticles were tested in vitro on HCC cells to evaluate their anticancer efficacy compared to free drug. Furthermore, the enhanced in vivo efficacy of lenvatinib-loaded nanoparticles on nude mice HCC xenograft models was demonstrated by evaluating tumor burdens, apoptotic markers and histological scores after administration of lenvatinib-nanoparticles via intraperitoneal or oral route. Finally, in vivo biodistribution studies were performed, demonstrating the ability of the prepared drug delivery systems to significantly accumulate in the solid tumor by active targeting, due to the presence of biotin on the nanoparticle surface.

Photochemical synthesis, characterization, and electrochemical sensing properties of CD-AuNP nanohybrids.

Among the existing nanosystems used in electrochemical sensing, gold nanoparticles (AuNPs) have attracted considerable attention owing to their intriguing chemical and physical properties such as good electrical conductivity, high electrocatalytic activity, and high surface-to-volume ratio. However, despite these useful characteristics, there are some issues due to their instability in solution that can give rise to aggregation phenomena and the use of hazardous chemicals in the most common synthetic procedures. With an aim to find a solution to these issues, recently, we prepared and characterized carbon dots (CDs), from olive solid wastes, and employed them as reducing and capping agents in photo-activated AuNP synthesis, thus creating CD-Au nanohybrids. These nanomaterials appear extremely stable in aqueous solutions at room temperature, are contemporary, and have been obtained using CDs, which are exclusively based on non-toxic elements, with an additional advantage of being generated from an otherwise waste material. In this paper, the synthesis and characterization of CD-Au nanohybrids are described, and the electrochemical experiments for hydroquinone detection are discussed. The results indicate that CD-Au acts as an efficient material for sensing hydroquinone, matching a wide range of interests in science from industrial processes to environmental pollution.

Structural properties and microbial diversity of the biofilm colonizing plastic substrates in Terra Nova Bay (Antarctica).

Microbial colonization on plastic polymers has been extensively explored, however the temporal dynamics of biofilm community in Antarctic environments are almost unknown. As a contribute to fill this knowledge gap, the structural characteristics and microbial diversity of the biofilm associated with polyvinyl chloride (PVC) and polyethylene (PE) panels submerged at 5 m of depth and collected after 3, 9 and 12 months were investigated in four coastal sites of the Ross Sea. Additional panels placed at 5 and 20 m were retrieved after 12 months. Chemical characterization was performed by FTIR-ATR and Raman (through Surface-Enhanced Raman Scattering, SERS) spectroscopy. Bacterial community composition was quantified at a single cell level by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) and Confocal Laser Scanning Microscopy (CLSM); microbial diversity was assessed by 16S rRNA gene sequencing. This multidisciplinary approach has provided new insights into microbial community dynamics during biofouling process, shedding light on the biofilm diversity and temporal succession on plastic substrates in the Ross Sea. Significant differences between free-living and microbial biofilm communities were found, with a more consolidated and structured community composition on PVC compared to PE. Spectral features ascribable to tyrosine, polysaccharides, nucleic acids and lipids characterized the PVC-associated biofilms. Pseudomonadota (among Gamma-proteobacteria) and Alpha-proteobacteria dominated the microbial biofilm community. Interestingly, in Road Bay, close to the Italian "Mario Zucchelli" research station, the biofilm growth - already observed during summer season, after 3 months of submersion - continued afterwards leading to a massive microbial abundance at the end of winter (after 12 months). After 3 months, higher percentages of Gamma-proteobacteria in Road Bay than in the not-impacted site were found. These observations lead us to hypothesize that in this site microbial fouling developed during the first 3 months could serve as a starter pioneering community stimulating the successive growth during winter.

PCR-Free Innovative Strategies for SARS-CoV-2 Detection.

The pandemic outbreak caused by SARS-CoV-2 coronavirus brought a crucial issue in public health causing up to now more than 600 million infected people and 6.5 million deaths. Conventional diagnostic methods are based on quantitative reverse transcription polymerase chain reaction (RT-qPCR assay) and immuno-detection (ELISA assay). However, despite these techniques have the advantages of being standardized and consolidated, they keep some main limitations in terms of accuracy (immunoassays), time/cost consumption of analysis, the need for qualified personnel, and lab constrain (molecular assays). There is crucial the need to develop new diagnostic approaches for accurate, fast and portable viral detection and quantification. Among these, PCR-free biosensors represent the most appealing solution since they can allow molecular detection without the complexity of the PCR. This will enable the possibility to be integrated in portable and low-cost systems for massive and decentralized screening of SARS-CoV-2 in a point-of-care (PoC) format, pointing to achieve a performant identification and control of infection. In this review, the most recent approaches for the SARS-CoV-2 PCR-free detection are reported, describing both the instrumental and methodological features, and highlighting their suitability for a PoC application.

Structural and antibacterial studies of novel ZnO and ZnxMn(1-x)O nanostructured titanium scaffolds for biomedical applications.

In the biomedical field, the demand for the development of broad-spectrum biomaterials able to inhibit bacterial growth is constantly increasing. Chronic infections represent the most serious and devastating complication related to the use of biomaterials. This is particularly relevant in the orthopaedic field, where infections can lead to implant loosening, arthrodesis, amputations and sometimes death. Antibiotics are the conventional approach for implanted-associated infections, but they have the limitation of increasing antibiotic resistance, a critical worldwide healthcare issue. In this context, the development of anti-infective biomaterials and infection-resistant surfaces can be considered the more effective strategy to prevent the implant colonisation and biofilm formation by bacteria, so reducing the occurrence of implant-associated infections. In the last years, inorganic nanostructures have become extremely appealing for chemical modifications or coatings of Ti surfaces, since they do not generate antibiotic resistance issues and are featured by superior stability, durability, and full compatibility with the sterilization process. In this work, we present a simple, rapid, and cheap chemical nanofunctionalization of titanium (Ti) scaffolds with colloidal ZnO and Mn-doped ZnO nanoparticles (NPs), prepared by a sol-gel method, exhibiting antibacterial activity. ZnO NPs and ZnxMn(1-x)O NPs formation with a size around 10-20nm and band gap values of 3.42 eV and 3.38 eV, respectively, have been displayed by characterization studies. UV-Vis, fluorescence, and Raman investigation suggested that Mn ions acting as dopants in the ZnO lattice. Ti scaffolds have been functionalized through dip coating, obtaining ZnO@Ti and ZnxMn(1-x)O@Ti biomaterials characterized by a continuous nanostructured film. ZnO@Ti and ZnxMn(1-x)O@Ti displayed an enhanced antibacterial activity against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Pseudomonas aeruginosa (P. aeruginosa) bacterial strains, compared to NPs in solution with better performance of ZnxMn(1-x)O@Ti respect to ZnO@Ti. Notably, it has been observed that ZnxMn(1-x)O@Ti scaffolds reach a complete eradication for S. aureus and 90 % of reduction for P. aeruginosa. This can be attributed to Zn2+ and Mn2+ metal ions release (as observed by ICP MS experiments) that is also maintained over time (72 h). To the best of our knowledge, this is the first study reported in the literature describing ZnO and Mn-doped ZnO NPs nanofunctionalized Ti scaffolds with improved antibacterial performance, paving the way for the realization of new hybrid implantable devices through a low-cost process, compatible with the biotechnological industrial chain method.

Physiologic Response Evaluation of Human Foetal Osteoblast Cells within Engineered 3D-Printed Polylactic Acid Scaffolds.

Large bone defect treatments have always been one of the important challenges in clinical practice and created a huge demand for more efficacious regenerative approaches. The bone tissue engineering (BTE) approach offered a new alternative to conventional bone grafts, addressing all clinical needs. Over the past years, BTE research is focused on the study and realisation of new biomaterials, including 3D-printed supports to improve mechanical, structural and biological properties. Among these, polylactic acid (PLA) scaffolds have been considered the most promising biomaterials due to their good biocompatibility, non-toxic biodegradability and bioresorbability. In this work, we evaluated the physiological response of human foetal osteoblast cells (hFOB), in terms of cell proliferation and osteogenic differentiation, within oxygen plasma treated 3D-printed PLA scaffolds, obtained by fused deposition modelling (FDM). A mechanical simulation to predict their behaviour to traction, flexural or torque solicitations was performed. We found that: 1. hFOB cells adhere and grow on scaffold surfaces; 2. hFOB grown on oxygen plasma treated PLA scaffolds (PLA_PT) show an improvement of cell adhesion and proliferation, compared to not-plasma treated scaffolds (PLA_NT); 3. Over time, hFOB penetrate along strands, differentiate, and form a fibrous matrix, tissue-like; 4. 3D-printed PLA scaffolds have good mechanical behaviour in each analysed configuration. These findings suggest that 3D-printed PLA scaffolds could represent promising biomaterials for medical implantable devices in the orthopaedic field.

Future Prospects of Luminescent Silicon Nanowires Biosensors.

In this paper, we exploit the perspective of luminescent Si nanowires (NWs) in the growing field of commercial biosensing nanodevices for the selective recognition of proteins and pathogen genomes. We fabricated quantum confined fractal arrays of Si NWs with room temperature emission at 700 nm obtained by thin-film, metal-assisted, chemical etching with high production output at low cost. The fascinating optical features arising from multiple scattering and weak localization of light promote the use of Si NWs as optical biosensing platforms with high sensitivity and selectivity. In this work, label-free Si NW optical sensors are surface modified for the selective detection of C-reactive protein through antigen-gene interaction. In this case, we report the lowest limit of detection (LOD) of 1.6 fM, fostering the flexibility of different dynamic ranges for detection either in saliva or for serum analyses. By varying the NW surface functionalization with the specific antigen, the luminescence quenching of NW biosensors is used to measure the hepatitis B-virus pathogen genome without PCR-amplification, with an LOD of about 20 copies in real samples or blood matrix. The promising results show that NW optical biosensors can detect and isolate extracellular vesicles (EV) marked with CD81 protein with unprecedented sensitivity (LOD 2 × 105 sEV/mL), thus enabling their measurement even in a small amount of blastocoel fluid.

Molecular Fingerprinting of the Omicron Variant Genome of SARS-CoV-2 by SERS Spectroscopy.

The continuing accumulation of mutations in the RNA genome of the SARS-CoV-2 virus generates an endless succession of highly contagious variants that cause concern around the world due to their antibody resistance and the failure of current diagnostic techniques to detect them in a timely manner. Raman spectroscopy represents a promising alternative to variants detection and recognition techniques, thanks to its ability to provide a characteristic spectral fingerprint of the biological samples examined under all circumstances. In this work we exploit the surface-enhanced Raman scattering (SERS) properties of a silver dendrite layer to explore, for the first time to our knowledge, the distinctive features of the Omicron variant genome. We obtain a complex spectral signal of the Omicron variant genome where the fingerprints of nucleobases in nucleosides are clearly unveiled and assigned in detail. Furthermore, the fractal SERS layer offers the presence of confined spatial regions in which the analyte remains trapped under hydration conditions. This opens up the prospects for a prompt spectral identification of the genome in its physiological habitat and for a study on its activity and variability.

SARS-CoV-2 and omicron variant detection with a high selectivity, sensitivity, and low-cost silicon bio-nanosensor.

The recent SARS-CoV-2 pandemic has highlighted the urgent need for novel point-of-care devices to be promptly used for a rapid and reliable large screening analysis of several biomarkers like genetic sequences and antibodies. Currently, one of the main limitations of rapid tests is the high percentage of false negatives in the presence of variants and, in particular for the Omicron one. We demonstrate in this work the detection of SARS-CoV-2 and the Omicron variant with a cost-effective silicon nanosensor enabling high sensitivity, selectivity, and fast response. We have shown that a silicon (Si) nanowires (NW) platform detects both Sars-CoV-2 and its Omicron variant with a limit of detection (LoD) of four effective copies (cps), without any amplification of the genome, and with high selectivity. This ultrasensitive detection of 4 cps allows to obtain an extremely early diagnosis paving the way for efficient and widespread tracking. The sensor is made with industrially compatible techniques, which in perspective may allow easy and cost-effective industrialization.

Structural organization and phase behaviour of 1-butyl-3-methylimidazolium hexafluorophosphate: an high pressure Raman spectroscopy study.

The complexity of the phase diagram of a representative room temperature ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF(6)]) is explored by means of Raman spectroscopy at high pressure (up to 1000 MPa) and high temperature (from room temperature to 100 °C) conditions. The first experimental evidence of the existence of a second crystalline phase for this salt at high pressure conditions is provided. By comparing the low frequency vibrational bands for the liquid state and the two observed crystalline phases, we confirm the scenario that considers the crystal polymorphism in this class of materials as a consequence of the rotational isomerism of the butyl chain. Furthermore the pressure dependence of other vibrational bands indicates the existence of a structural rearrangement across p≈ 50 MPa at ambient temperature.

Visualization of Directional Beaming of Weakly Localized Raman from a Random Network of Silicon Nanowires.

Disordered optical media are an emerging class of materials that can strongly scatter light. These materials are useful to investigate light transport phenomena and for applications in imaging, sensing and energy storage. While coherent light can be generated using such materials, its directional emission is typically hampered by their strong scattering nature. Here, the authors directly image Rayleigh scattering, photoluminescence and weakly localized Raman light from a random network of silicon nanowires via real-space microscopy and Fourier imaging. Direct imaging enables us to gain insight on the light transport mechanisms in the random material, to visualize its weak localization length and to demonstrate out-of-plane beaming of the scattered coherent Raman light. The direct visualization of coherent light beaming in such random networks of silicon nanowires offers novel opportunities for fundamental studies of light propagation in disordered media. It also opens venues for the development of next generation optical devices based on disordered structures, such as sensors, light sources, and optical switches.

Fluorescent Biosensors Based on Silicon Nanowires.

Nanostructures are arising as novel biosensing platforms promising to surpass current performance in terms of sensitivity, selectivity, and affordability of standard approaches. However, for several nanosensors, the material and synthesis used make the industrial transfer of such technologies complex. Silicon nanowires (NWs) are compatible with Si-based flat architecture fabrication and arise as a hopeful solution to couple their interesting physical properties and surface-to-volume ratio to an easy commercial transfer. Among all the transduction methods, fluorescent probes and sensors emerge as some of the most used approaches thanks to their easy data interpretation, measure affordability, and real-time in situ analysis. In fluorescent sensors, Si NWs are employed as substrate and coupled with several fluorophores, NWs can be used as quenchers in stem-loop configuration, and have recently been used for direct fluorescent sensing. In this review, an overview on fluorescent sensors based on Si NWs is presented, analyzing the literature of the field and highlighting the advantages and drawbacks for each strategy.

Liquid Structure of a Water-in-Salt Electrolyte with a Remarkably Asymmetric Anion.

Water-in-salt systems, i.e., super-concentrated aqueous electrolytes, such as lithium bis(trifluoromethanesulfonyl)imide (21 mol/kgwater), have been recently discovered to exhibit unexpectedly large electrochemical windows and high lithium transference numbers, thus paving the way to safe and sustainable charge storage devices. The peculiar transport features in these electrolytes are influenced by their intrinsically nanoseparated morphology, stemming from the anion hydrophobic nature and manifesting as nanosegregation between anions and water domains. The underlying mechanism behind this structure-dynamics correlation is, however, still a matter of strong debate. Here, we enhance the apolar nature of the anions, exploring the properties of the aqueous electrolytes of lithium salts with a strongly asymmetric anion, namely, (trifluoromethylsulfonyl)(nonafluorobutylsulfonyl) imide. Using a synergy of experimental and computational tools, we detect a remarkable level of structural heterogeneity at a mesoscopic level between anion-rich and water-rich domains. Such a ubiquitous sponge-like, bicontinuous morphology develops across the whole concentration range, evolving from large fluorinated globules at high dilution to a percolating fluorous matrix intercalated by water nanowires at super-concentrated regimes. Even at extremely concentrated conditions, a large population of fully hydrated lithium ions, with no anion coordination, is detected. One can then derive that the concomitant coexistence of (i) a mesoscopically segregated structure and (ii) fully hydrated lithium clusters disentangled from anion coordination enables the peculiar lithium diffusion features that characterize water-in-salt systems.

Cost-Effective Fabrication of Fractal Silicon Nanowire Arrays.

Silicon nanowires (Si NWs) emerged in several application fields as a strategic element to surpass the bulk limits with a flat compatible architecture. The approaches used for the Si NW realization have a crucial impact on their final performances and their final cost. This makes the research on a novel and flexible approach for Si NW fabrication a crucial point for Si NW-based devices. In this work, the novelty is the study of the flexibility of thin film metal-assisted chemical etching (MACE) for the fabrication of Si NWs with the possibility of realizing different doped Si NWs, and even a longitudinal heterojunction p-n inside the same single wire. This point has never been reported by using thin metal film MACE. In particular, we will show how this approach permits one to obtain a high density of vertically aligned Si NWs with the same doping of the substrate and without any particular constraint on doping type and level. Fractal arrays of Si NWs can be fabricated without any type of mask thanks to the self-assembly of gold at percolative conditions. This Si NW fractal array can be used as a substrate to realize controllable artificial fractals, integrating other interesting elements with a cost-effective microelectronics compatible approach.

Ultrathin Silicon Nanowires for Optical and Electrical Nitrogen Dioxide Detection.

The ever-stronger attention paid to enhancing safety in the workplace has led to novel sensor development and improvement. Despite the technological progress, nanostructured sensors are not being commercially transferred due to expensive and non-microelectronic compatible materials and processing approaches. In this paper, the realization of a cost-effective sensor based on ultrathin silicon nanowires (Si NWs) for the detection of nitrogen dioxide (NO2) is reported. A modification of the metal-assisted chemical etching method allows light-emitting silicon nanowires to be obtained through a fast, low-cost, and industrially compatible approach. NO2 is a well-known dangerous gas that, even with a small concentration of 3 ppm, represents a serious hazard for human health. We exploit the particular optical and electrical properties of these Si NWs to reveal low NO2 concentrations through their photoluminescence (PL) and resistance variations reaching 2 ppm of NO2. Indeed, these Si NWs offer a fast response and reversibility with both electrical and optical transductions. Despite the macro contacts affecting the electrical transduction, the sensing performances are of high interest for further developments. These promising performances coupled with the scalable Si NW synthesis could unfold opportunities for smaller sized and better performing sensors reaching the market for environmental monitoring.

A Novel Silicon Platform for Selective Isolation, Quantification, and Molecular Analysis of Small Extracellular Vesicles.

INTRODUCTION: Small extracellular vesicles (sEVs), thanks to their cargo, are involved in cellular communication and play important roles in cell proliferation, growth, differentiation, apoptosis, stemness and embryo development. Their contribution to human pathology has been widely demonstrated and they are emerging as strategic biomarkers of cancer, neurodegenerative and cardiovascular diseases, and as potential targets for therapeutic intervention. However, the use of sEVs for medical applications is still limited due to the selectivity and sensitivity limits of the commonly applied approaches. METHODS: Novel sensing solutions based on nanomaterials are arising as strategic tools able to surpass traditional sensor limits. Among these, Si nanowires (Si NWs), realized with cost-effective industrially compatible metal-assisted chemical etching, are perfect candidates for sEV detection. RESULTS: In this paper, the realization of a selective sensor able to isolate, concentrate and quantify specific vesicle populations, from minimal volumes of biofluid, is presented. In particular, this Si NW platform has a detection limit of about 2×105 sEVs/mL and was tested with follicular fluid and blastocoel samples. Moreover, the possibility to detach the selectively isolated sEVs allowing further analyses with other approaches was demonstrated by SEM analysis and several PCRs performed on the RNA content of the detached sEVs. DISCUSSION: This platform overcomes the limit of detection of traditional methods and, most importantly, preserves the biological content of sEVs, opening the route toward a reliable liquid biopsy analysis.