Biosensing performance in graphene-derived field-effect transistors (BioFETs) is widely attributed to surface chemistry, yet the role of the underlying charge transport mechanism remains poorly understood. This work establishes a direct correlation between disorder-driven transport and biosensing transduction in vertical graphene (VG) and nanocrystalline graphite (NCG) FET devices. Temperature-dependent electrical characterization (15–500 K) reveals a hybrid transport regime: three-dimensional Mott variable-range hopping below 240 K, transitioning to thermally activated Arrhenius-type conduction above 240 K. The extracted VRH parameters characteristic temperature T0, localization length ξ, and density of states N(EF) quantify fundamentally distinct disorder landscapes: VG operates in a strongly localized, edge-dominated regime, while NCG forms a continuous percolative network with greater transport stability. Surface functionalization via PASE and amine-terminated ssDNA probes, followed by DNA hybridization across four nucleobase systems, demonstrates that the sequence-dependent electrical response is mechanistically interpretable within the VRH–transconductance framework. NCG transduces biomolecular binding through direct charge transfer and hopping pathway perturbation, whereas VG responds through interfacial electrostatic reorganization. These results introduce a unified VRH–transconductance–sensing framework, providing a rational physical basis for next-generation graphene BioFET design.

This letter introduces LYT-Net, a novel lightweight transformer-based model for low-light image enhancement. LYT-Net consists of several layers and detachable blocks, including our novel blocks-Channel-Wise Denoiser (CWD) and Multi-Stage Squeeze & Excite Fusion (MSEF)-along with the traditional Transformer block, Multi-Headed Self-Attention (MHSA). In our method we adopt a dual-path approach, treating chrominance channels U and V and luminance channel $Y$ as separate entities to help the model better handle illumination adjustment and corruption restoration. Our comprehensive evaluation on established LLIE datasets demonstrates that, despite its low complexity, our model outperforms recent LLIE methods.

Titanium dioxide thin films have been successfully coated on glass substrates using reactive magnetron sputtering and we highlight how different deposition parameters influence the crystalline structure and optical properties of the deposited layers. After the deposition process, amorphous films were obtained and after thermal treatments, the crystalline structure transformed to anatase and rutile forms, depending on the deposition parameters. The grown thin films were characterized by X-ray diffraction, atomic force microscopy, ellipsometry and UV-visible spectroscopy). In order to confirm the results obtained regarding the ellipsometric measurements, the OPTIFIT software was used to determine the variation of the refractive indices from the transmission spectrum measured by spectroscopy.

In this paper, we present a verification method to compare the hardware and etch performance of different Oxford Instruments dry etching systems to facilitate etch recipe transfer. The flow-pressure window and the chemical and physical flux within the same flow-pressure window were determined for each system. The chemical and physical fluxes were matched between the investigated systems to yield similar etch results. The method was tested using a continuous SF 6 /O2 silicon etching recipe.

This study is part of an extended investigation into the quantitative detection of therapeutic molecules with antineoplastic properties, specifically focusing on bleomycin. The objective is to minimize adverse effects while maximizing therapeutic effectiveness. We are presenting the results for bleomycin detection, in terms of cyclic voltammetry and electrochemical impedance spectroscopy. We are continuing an approach we have recently started, of an electrochemical biosensor based on graphene, which is evidenced to be a revolutionary nanomaterial. The vertical graphene biosensor exhibited improved sensitivity, faster response, faster occurrence of the chemical reactions, and higher electrode surface conductivity, than the classical gold IDE sensor. The construction of the electrochemical sensor involved growing vertically aligned graphene nanosheets on the conductive surface of interdigitated electrodes. The results for bleomycin detection emphasized that a simpler surface modification method proved to be more efficient.

This paper explores the synthesis methods and properties of vertically aligned graphene nanosheets (VG) and their applications. VG is obtained using the plasma-enhanced chemical vapor deposition (PECVD) method, and different VG types with other properties can be obtained by changing the process parameters. VG is part of the graphene family; properties such as excellent electrical conductivity, thermal conductivity, chemical stability, and a large, specific surface area make it suitable for biomedical applications. Examples of biomedical applications in which VG is used are biosensors, electrochemical sensors, modified surfaces for bone growth, regeneration, and for antimicrobial effects. First, VG's properties are reviewed in this review article, and then the most recent progress in its applications and related sciences and technologies are discussed.

The progress of advanced materials has invoked great interest in promising novel biosensing applications. Field-effect transistors (FETs) are excellent options for biosensing devices due to the variability of the utilized materials and the self-amplifying role of electrical signals. The focus on nanoelectronics and high-performance biosensors has also generated an increasing demand for easy fabrication methods, as well as for economical and revolutionary materials. One of the innovative materials used in biosensing applications is graphene, on account of its remarkable properties, such as high thermal and electrical conductivity, potent mechanical properties, and high surface area to immobilize the receptors in biosensors. Besides graphene, other competing graphene-derived materials (GDMs) have emerged in this field, with comparable properties and improved cost-efficiency and ease of fabrication. In this paper, a comparative experimental study is presented for the first time, for FETs having a channel fabricated from three different graphenic materials: single-layer graphene (SLG), graphene/graphite nanowalls (GNW), and bulk nanocrystalline graphite (bulk-NCG). The devices are investigated by scanning electron microscopy (SEM), Raman spectroscopy, and I-V measurements. An increased electrical conductance is observed for the bulk-NCG-based FET, despite its higher defect density, the channel displaying a transconductance of up to ≊4.9×10−3 A V−1, and a charge carrier mobility of ≊2.86×10−4 cm2 V−1 s−1, at a source-drain potential of 3 V. An improvement in sensitivity due to Au nanoparticle functionalization is also acknowledged, with an increase of the ON/OFF current ratio of over four times, from ≊178.95 to ≊746.43, for the bulk-NCG FETs.

In this paper, we show in a series of experiments on 10 nm thick SnS thin film-based back-gate transistors that in the absence of the gate voltage, the drain current versus drain voltage ( I D – V D ) dependence is characterized by a weak drain current and by an ambipolar transport mechanism. When we apply a gate voltage as low as 1 μ V, the current increases by several orders of magnitude and the I D – V D dependence changes drastically, with the SnS behaving as a p -type semiconductor. This happens because the current flows from the source (S) to the drain (D) electrode through a discontinuous superficial region of the SnS film when no gate voltage is applied. On the contrary, when minute gate voltages are applied, the vertical electric field applied to the multilayer SnS induces a change in the flow path of the charge carriers, involving the inner and continuous SnS layer in the electrical conduction. Moreover, we show that high gate voltages can tune significantly the SnS bandgap.

Vertical graphene (VG) is one of the newest forms of graphite, being part of the family of carbon materials. Due to its unique characteristics and physiochemical properties including large specific surface area, high electric conductivity and intense electrochemical activity, it has attracted the interest in many applications, specifically in the medical field. VG is a two-dimensional graphitic sheet, vertically aligned to the substrate. Its electrical characteristics make VG a good choice for using it in the development of electrochemical biosensors for cellular identification. VG is obtained using plasma enhanced chemical vapor deposition. Scanning electron microscopy was used to study the morphological structure of the grown vertical graphene, Raman spectroscopy was performed to identify the characteristic vibrational modes and to assess the quality of the deposited films and electrochemical impedance spectroscopy was used for electrical characterization of the vertical graphene. In order to assess the biological effect of VG samples and to confirm that the VG can be used for cellular identification, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium-salt assay was used on a cell line of U251 human glioblastoma (CLS).

Their nanocrystalline structure and good electrical conductivity, makes nanocrystalline graphite thin films an asset in a wide range of applications. Their morpho-structural and electrical properties are herein studied with respect to the substrate temperature during their plasma-enhanced chemical vapor deposition. Although the thin films present similar morpho-structural properties, a significant improvement in electrical conductivity is observed for a higher growth temperature.

Nanostructured silicon substrate has been intensively studied in the last years, as promising platform for Surface-enhanced Raman scattering applications. Si based conical shape nanostructures - Si nanotrees, decorated with small Ag nanocubes, are used to improve the Raman signal for molecules detection (e.g. organic dyes). Here in, substrates with a discontinuous film of Ag, deposited on the nanostructured silicon, are fabricated in order to improve the Raman signal even more. Morphological properties are analyzed by using SEM images. Absorbance properties of the fabricated nanocubes are also investigated. Crystal violet was chosen to evaluate the performances of our fabricated detection platform. A good value of $1.5\times 10^{8}$ for enhancement factor, in the case of modified silicon nanotrees like substrate, is determined.

Many advances in fabrication processes at micro and nanoscale in the past two decades were possible due to scanning electron microscopy, which is now an indispensable tool for analyzing and fabricating new nanostructures and nanomaterials. The development of very efficient in-lens detectors for SEM and the capability to use low energy electron probes are the gateway to the revelation of new features and new properties of nanomaterials that have been hidden by the use of high accelerating voltages and large interaction of volume, in the high-resolution SEM. Electron beams have been used for lithography for decades and pattern generators can be fitted to all modern SEMs, converting them in very powerful nanolithographic tools, without degrading or limiting their imaging capabilities. The SEM became a very versatile tool for micro and nanofabrication, the same equipment used for fabrication being used to view the resulting nanostructures. Electron Beam Lithography (EBL) is one of the highest resolution lithographic technologies and a key technique for fabrication of nanoelectronic devices, allowing direct patterning of structures with critical dimensions down to 10 nm [1]. Apart of resolution, a very important point of EBL is that it can be easily implemented in a research laboratory by converting a scanning electron microscope (SEM) for lithography with an external pattern generator. To illustrate the patterning capabilities of electron microscopy, in this review we describe the EBL based fabrication processes of some nano-devices like field effect transistors on graphene and other 2D materials.

Electrochemical sensors based on vertically oriented graphene (VG) have gained attention in recent years due to the unique properties of VG, such as its large surface area, biocompatibility, and high electrical conductivity. In this paper, we studied an electrochemical sensor with interdigitated electrodes modified with VG as an essential interface for the identification of two types of human colon adenocarcinoma cells: SW403 (high invasiveness) and HT29 (low invasiveness). Both cell lines have epithelial morphology, and we tested the electrochemical sensor on different concentrations of SW403 and HT29 cells. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for morphological characterization of VG deposited on the working interdigitated electrodes, Raman spectroscopy was used to evaluate the graphitic nature of the VG growth on electrodes, and atomic force microscopy (AFM) was used to study the rugosity of the VG. Fourier-transform infrared spectrometry (FTIR) was used to study the configurations of the chemical bonds in the VG used for the working electrode of the electrochemical sensor. Vertically oriented graphene improves the sensor’s response on the cell lines, as evaluated by electrochemical impedance spectroscopy (EIS).

Monitoring and controlling infection is required in order to prevent the progression of the coronavirus severe acute respiratory syndrome 2(SARS-CoV-2). To accomplish this goal, the development and implementation of sensitive, quick and accurate diagnosti

As metasurfaces begin to find industrial applications there is a need to develop scalable and cost-effective fabrication techniques which offer sub-100 nm resolution while providing high throughput and large area patterning. Here we demonstrate the use of UV-Nanoimprint Lithography and Deep Reactive Ion Etching (Bosch and Cryogenic) towards this goal. Robust processes are described for the fabrication of silicon rectangular pillars of high pattern fidelity. To demonstrate the quality of the structures, metasurface lenses, which demonstrate diffraction limited focusing and close to theoretical efficiency for NIR wavelengths λ ∈ (1.3 μm, 1.6 μm), are fabricated. We demonstrate a process which removes the characteristic sidewall surface roughness of the Bosch process, allowing for smooth 90-degree vertical sidewalls. We also demonstrate that the optical performance of the metasurface lenses is not affected adversely in the case of Bosch sidewall surface roughness with 45 nm indentations (or scallops). Next steps of development are defined for achieving full wafer coverage.

In this work, the growth process of self-sustained vertically aligned carbon nanotubes (VA-CNTs) is investigated in full: from bare Si wafers to fully grown VA-CNTs on 4″ wafers. Each developmental step, from supporting and catalyst layers’ depositions to CNT growth, is analyzed through X-ray diffraction, X-ray reflectivity, and scanning electron microscopy, respectively. The crystalline structure of the titanium nitride supporting layer is investigated through grazing incidence X-ray diffraction, while X-ray reflectivity provides information regarding the density, thickness, and roughness of the titanium nitride layer via extended Fourier analysis. Further, the nickel layers’ and CNTs’ morphologies are investigated by scanning electron microscopy.

In this paper, we present for the first time a field-effect-transistor (FET) having a 10 nm thick tin sulfide (SnS) channel fabricated at the wafer scale with high reproducibility. SnS-based FETs are in on-state for increasing positive back-gate voltages up to 6 V, whereas the off-state is attained for negative back-gate voltages not exceeding -6 V, the on/off ratio being in the range 10(2)-10(3) depending on FET dimensions. The SnS FETs show a subthreshold slope (SS) below 60 mV/decade thanks to the in-plane ferroelectricity of SnS and attaining a minimum value SS = 21 mV/decade. Moreover, the low SS values can be explained by the existence of a negative value of the capacitance of the SnS thin film up to 10 GHz (for any DC bias voltage between 1 and 5 V), with the minimum value being -12.87 pF at 0.1 GHz.

Investigations on the oxygen plasma treatment of graphene have been already reported in literature, but in this paper, as a novelty, we present a structural conversion of single layer graphene by O2 plasma treatment. Graphene Oxide is a chemically controlled graphene with hydroxyl, epoxy, carboxyl and carbonyl groups. Low O2 plasma treatment has been evidenced to be an efficient method to introduce defects and active groups in graphene structure with significantly contribution in biosensor area for detecting pathogens and biomolecules. Single Layer Graphene was grown on copper substrate by Chemical Vapor Deposition method and then transferred by wet chemical technique on gold substrate. Pristine Graphene was exposed to a downstream oxygen plasma and we have investigated the modification of the pristine graphene using Scanning Electron Microscopy (SEM), Raman Spectroscopy, Fourier Transform-Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), and X-Ray Photoelectron Spectroscopy (XPS) to examine the quality and structure modification of pristine graphene.

Monitoring and controlling infection is required in order to prevent the progression of the coronavirus severe acute respiratory syndrome 2(SARS-Co- V-2). To accomplish this goal, the development and implementation of sensitive, quick and accurate diagnostic methods are essential. Electrochemical sensors have exposed large application possibilities in biological detection due to the advantages of high sensitivity, short time-consuming and specificity. Here, we report the improvement of a sensitive electrochemical sensor capable of detecting the presence of the SARS-CoV-2 virus using graphene-modified interdigitated working electrodes functionalized with antibodies targeting the SARS-CoV-2 nucleocapsid protein (N protein).

3D tumor cell cultures are currently emerging as the novel standard for cytotoxicity testing as well as in vitro molecular studies, but various solutions are available to generate them. The aim of this study was to test whether there is one-fits-all solution to generate tumor spheroids for further studies. We used three breast tumor cell lines (MCF-7, MDA-MB-231, MDA-MB-361) and one glioblastoma cell line (U87), as comparison for MDA-MB-361 which is a secondary (metastatic) brain tumor. Different hydrogels (Matrigel® Corning, TrueGel3D -1, -6,-7 with or w/o RGD adhesion peptide® Merck, and TrueGel3D® HTS Hydrogel Plates®Merck) were tested for spheroid formation, as well as ultra-low attachment surface 24 well-plates ®Corning (no gels). Cells were seeded in two concentrations (300 and 3000/cm2) and documented daily for the first 5 days, than weekly for spheroid formation. Viability was tested using dual fluorescein diacetate/propidium iodide stain. For higher cell concentrations, presence of spheroids can be documented as early as 5 days, but at least 7 days are recommended. Once formed, spheroids can be maintained more than 28 days, with twice a week cell medium change. Presence of organic molecules (basement membrane matrix or RGD peptide) in the gel impaired formation of tumor spheroids for aggressive cell lines (MDA-MB-261 and U87) and yielded mixed cultures (2D and spheroids) for the rest. Also, higher stiffness and the presence of a non-degradable cell linker prevented proliferation of cells and formation of spheroids, regardless of cell type. A crosslinker gradient, although favored formation of all tested breast cancer spheroids, interfered with formation of spheroids for U87 cells. Finally, ultra-low adherence plates allowed consistent formation of spheroids only for MCF-7 cells, whereas for the rest, irregular cell aggregates were observed at higher cell concentrations. Dextran-based polymers can be used for tumor spheroid formation regardless of cell type, provided that no adhesion peptides are added.