Seznam abstraktů 2025: POSTEROVÁ SEKCE E

Dielectric barrier discharges (DBD) are an important source of plasma in industry and research. Commonly used high voltage (HV) power supply frequencies range from tens of Hz to hundreds of kHz in ambient air. Continuous DBD at MHz frequencies in ambient air leads to rapid overheating. The solution to overheating is the use of a dual-frequency (DF) HV generator with the possibility of combining low frequencies (tens of kHz) and high MHz frequencies.
In the literature, DF mode was reported to power atmospheric pressure DBDs in, e.g. argon at 13.56 MHz. However, commercially available power supplies do not have sufficient voltage amplitude. Thus, we developed novel resonant MHz transformers suitable for DF applications. When the MHz component is pulsed with a sufficiently low duty cycle, the overheating is rapidly reduced. Thus, the discharge becomes suitable for plasma treatment of various materials.
The project's aim is to investigate the DF-DBD behaviour for potential further application in novel material processing. In this work, we studied the interaction of DF-DBD with chosen model materials from the class of metal, glass, ceramic and polymer. The main goal was to investigate the working domain of DF-DBD, in terms of discharge gap, ignition voltage, voltage range for stable generation of DF-DBD and other limitations during interaction with different classes of materials.
ACKNOWLEDGEMENTS: This research was supported by project No. GF25-20010L, funded by the Czech Science Foundation (GAČR) and by project LM2023039, funded by the Ministry of Education, Youth and Sports of the Czech Republic.

Accurate quantification of nanoparticles is essential for material standardization, environmental monitoring, and toxicological assessment. Here, we present Evaporated Volume Analysis (EVA). EVA is a simple, absolute quantification method that counts all nanoparticles in a macroscopic droplet after solvent evaporation [1]. An optical microscope scans the dried droplet. Images are stitched and nanoparticles counted via a convolutional neural network. Theoretical detection limits were derived from Poisson statistics and the distribution of nearest-neighbor distances. EVA proved compatible with various nanoparticle types and sample matrices, including biological fluids and organic solvents. Compared to other single-particle counting methods, EVA offers unique advantages: simplicity, robustness, and a straightforward uncertainty model. Its accuracy stems from nanoparticle counting, not from calibration curves or material-specific parameters. With microscope automation and a convolutional neural network, EVA holds promise as a scalable and generalizable approach for nanoparticle quantification.
REFERENCE: [1] Hlaváček et al., Anal. Chem. 2025, 97, 2588-2592.
ACKNOWLEDGMENT: This work was supported by the Czech Science Foundation (grant no. 24-11183S) and by the institutional support for long-term conceptual development of research organizations (RVO: 68081715), provided by the Institute of Analytical Chemistry of the Czech Academy of Sciences.

Lithography is an important step in the fabrication of ordered nanostructures. In order to process a large area, the selected fabrication method must have a high throughput and be low-cost. This can be achieved by employing nanosphere lithography (NSL). The basic principle of NSL is to deposit a single layer of spheres that serve as a mask through which the final nanostructure is etched. This work aims to demonstrate that NSL is a viable technique for fabricating GaN and InGaN triangular nanostructures, as well as nanowires. The whole fabrication process consists of depositing polystyrene spheres, depositing metal to cover the entire sample, and lifting off the spheres to expose the material beneath. In the final step, a SiCl₄/Ar plasma was used to finalise the triangular nanostructure, which can then be etched in an etchant to produce nanowires. For each step, it is necessary to find the optimal parameters to achieve reliable reproducibility. The entire fabrication process will be characterised using an electron microscope, cathodoluminescence spectroscopy and EDX. The resulting nanostructures should have a large surface area, which would be advantageous for applications in photocatalytic water splitting and various other applications, depending on the selected material.

Thin films of black metals prepared by magnetron sputtering in the presence of an inert gas atmosphere are formed with extreme porosity [1], which is a dominant parameter used in various applications, including solar energy harvesting, catalysis, gas sensing, and microelectronics [2, 3]. A challenging task for diagnostics of black metals is the determination and analysis of their porosity [4]. In this work, thin layers of porous nanostructures of Au and Ag were synthesized and subsequently annealed in vacuum at temperatures of 250 °C and 500 °C. Their porosity was analyzed by the Rutherford backscattering (RBS) method, which was used for different angles of incidence of ions (alpha particles with energy of 2 MeV). For each measured spectrum, a simulation was performed to determine the porosity level in a given direction. The analysis provided information on profiling of porosity of thin black Au and Ag films in different directions and depths, which is otherwise difficult to determine by other methods.
REFERENCES: [1] P. Hruška, J. More-Chevalier, M. Novotný, J. Čížek, O. Melikhova, L. Fekete, M. Poupon, J. Bulíř, L. Volfová, M. Butterling, M.O. Liedke, A. Wagner, P. Fitl, Journal of Alloys and Compounds 872 (2021) 159744; [2] R. Zhang, H. Olin, Porous Gold Films—A Short Review on Recent Progress, Materials (Basel) 7 (2014) 3834; [3] E. Kurowska-Tabor, K. Gawlak, K. Gawlak, K.E. Hnida-Gut, tarzyna E. Hnida-Gut, G.D. Sulka, Synthesis of porous thin silver films and their application for hydrogen peroxide sensing, Electrochimica Acta 213 (2016) 811; [4] M.R. Baklanov, K.P. Mogilnikov, A.S. Vishnevskiy, Challenges in porosity characterization of thin films: Cross-evaluation of different techniques, J. Vac. Sci. Technol. A41 (2023) 050802.

Two-dimensional transition metal carbides (MXenes) are among the most widely studied materials today, with applications spanning critical fields such as electrocatalysis, energy storage, photochemical processes, and biomedical sensing. Their high electrical conductivity, water dispersibility, and versatile surface functionalization capabilities make them a universal platform for applied 2D nanomaterials. Moreover, their ability to host additional catalytic sites enables the tuning of catalytic activity for specific chemical processes. However, achieving optimal performance requires a simple, rapid, and reliable method for decorating MXene nanoflakes with catalytic sites. In this work, a microwave-assisted solvothermal method was employed to decorate Ti₃C₂, Nb₂C, and V₂C MXene nanoflakes with single-atom catalytic sites of noble metals (Pt, Rh, Pd) to enhance their electrocatalytic performance in the hydrogen evolution reaction (HER). The modified MXene samples were characterized using XRD, HR-TEM, EDS, XPS, and Raman spectroscopy. Results showed that the treatment preserves the structural integrity of the nanoflakes while enabling the formation of either atomically dispersed metal sites or anchored nanoparticles, depending on the specific MXene and metal used. The modified MXene nanoflakes demonstrated significantly enhanced HER catalytic activity compared to pristine MXenes. Turnover frequencies of the catalytic sites were benchmarked against the values of platinum surface atoms. The proposed structures and catalytic efficiency of the single-atom sites were investigated using density functional theory calculations.
ASZ acknowledges the European Research Executive Agency (HORIZON-MSCA-2022-PF-01-01) grant 101108465 (P2XSACat Project). Authors also acknowledge the UFS Sustainable Materials Design and the CRC 1636 (Deutsche Forschungsgemeinschaft (DFG) - Project ID 510943930).

Homogeneous coverage of nanodiamond (ND) surfaces with hydroxyl groups is important for ensuring consistent physicochemical properties and enabling further chemical functionalization. Among various surface modification strategies, the Fenton reaction stands out as an efficient method for introducing -OH groups through in situ generation of hydroxyl radicals from hydrogen peroxide and iron salts. However, insufficient attention has been paid to the influence of the initial surface chemistry of ND on hydroxylation.
In this study, we performed a comparative investigation of four types of nanodiamonds: high-pressure high-temperature (HPHT) and detonation nanodiamonds (DND), each with either oxidized or hydrogenated surface termination. The aim was to determine whether the initial ND surface chemistry is significant and which initial chemical composition of the surface leads to the most effective and homogeneous hydroxylation under standard Fenton reaction conditions.
Complete chemical analysis of the surface and the degree and uniformity of surface hydroxylation were evaluated using zeta potential and dynamic light scattering, infrared and X-ray photoelectron spectroscopy, supplemented by thermal analysis with temperature-programmed desorption. The obtained complex data revealed that initially hydrogenated nanodiamonds—both HPHT-H and DND-H—achieved the highest density and homogeneity of hydroxyl groups after Fenton treatment, whereas oxidized counterparts exhibited lower hydroxylation efficiency and more heterogeneous surface chemistry. Based on these results, hydrogenated ND surface can be recommended as the optimal starting point for achieving uniform and efficient hydroxylation of nanodiamonds via the Fenton reaction.

Point defects in crystals may constitute the elemenary unit of quantum information, the quantum bits. Among these, the negatively charged nitrogen-vacancy (NV⁻) center in diamond has attracted considerable attention due to its stability at room temperature for quantum biosensing. Nanodiamonds are commonly synthesized by high-pressure, high-temperature (HPHT) methods. During post-synthesis cleaning, strong oxidizing acids (e.g., HNO₃, H₂SO₄, HClO₄) are employed, introducing various surface functional groups such as carboxyls. These surface groups can influence the charge state stability and operation of NV⁻ and offer possibilities for further chemical modification. One such modification is Hofmann degradation, a well-known organic reaction that enables the direct formation of amino groups from carboxyl functionalities via decarbonylation. This process yields primarily primary amine terminations, which can facilitate the formation of C−N−C bonds, thereby favorably affecting NV⁻ center stabilization. Carboxyl- and amino-functionalized nanodiamonds were annealed at 600 °C, 750 °C, and 850 °C for 10 minutes. The NV⁻/NV⁰ ratio in the fluorescence spectrum was monitored. Significant annealing-dependent variations in this ratio were observed. These differences are attributed to surface chemical transformations as confirmed by infrared (IR) spectroscopy and X-ray photoelectron spectroscopy (XPS).
ACKNOWLEDGEMENTS: The work was supported by the Quantum Information National Laboratory sponsored by National Research, Development and Innovation Fund (NKFIH) Grant No. 2022-2.1.1-NL-2022-00004. The research reported in this paper and carried out at Wigner Research Centre for Physics is supported by the infrastructure of the Hungarian Academy of Sciences.

Functionalizing cellulose materials and nanomaterials with ionic liquids (ILs) has emerged as a promising strategy for developing advanced functional materials with unique and tunable properties. ILs can be chemically bonded to the cellulose chain and the covalent attachment results in a material known as supported ionic liquids. They combine the advantageous characteristics of both components: the structural versatility, renewability, and biodegradability of cellulose with the customizable physicochemical properties of ILs.
In this work, we performed two approaches for cellulose functionalization with ILs The direct functionalization involved the reaction of cellulose with glycidyltrimethylammonium chloride under alkaline conditions, which led to the surface modification with quaternary ammonium groups. Key parameters influencing the efficiency of this process included the concentration of reactants and the reaction temperature [1]. The indirect functionalization followed a three-step protocol designed to introduce ammonium groups with varying alkyl chain lengths, which enabled greater control over the structural diversity of the functional groups introduce [2].
The obtained materials were subjected to physicochemical characterisation using the following methods: SEM; FTIR; TGA; DSC; low-temperature nitrogen adsorption/desorption and NMR. The materials obtained through two different functionalisation processes differ in terms of structure and other parameters, due to the varying content of ammonium compounds and the varying degree of development of these compounds.
ACKNOWLEDGEMENTS: This work was financed by the National Science Centre project SONATA 18, grant agreement number UMO-2022/47/D/ST8/02389.
REFERENCES: [1] MORAL, A., et.al. Fibers and Polymers. 2016, 17, 857-861; [2] WANG, X., et.al. ACS Applied Polymers Materials, 2024, 6, 12992-13001.

Polymer nanofibers are unique materials with a high specific surface area, porous structure, and the possibility of precise morphology control. These properties make them promising materials for medical applications, particularly in tissue engineering, as well as in technical fields including filtration, sensor technology, and composite reinforcement. Currently, nanofibers are mainly used in the form of flat membranes produced by DC electrospinning.
This work focuses on the production of nanofibers using AC electrospinning technology with high productivity and specific morphology. This is achieved, primarily, by replacing a physical and electrically active counter-electrode with a virtual collector. The possibility of using a virtual collector to form nanofiber structures without frictional forces opens the way to the production of advanced nanofiber structures, including low-volume cohesive linear formations.
Previous technologies for producing nanofiber yarns used a supporting core around which the nanofibers were wrapped. In the case of nanofibrous yarn without the supporting core, the method required contact of nanofibers with a mechanical collector during yarn formation, resulting in a higher volume of nanofibers needed to maintain the minimum strength necessary for removal from the collector. As a result, the minimum achievable fineness is limited and the material is excessively compacted in order to be able to transmit the necessary forces.
The presented work describes a method that enables the continuous production of linear nanofiber sliver directly in the virtual collector area of AC electrospinning technology, and without mechanical contact with any physical elements. The resulting unique structure is cohesive, with minimal twisting and no excessive compaction.
The described continuous technology has sufficient production speed for practical use, and the materials produced have application potential, particularly in medicine, where they can support cell cultivation and proliferation.

Due to their unique combination of properties and the ability to be modified not only through deposition parameters but also by intentional doping, carbon-based thin films prepared by PECVD represent a highly versatile class of materials with broad industrial applicability.
Given the significant influence of both doping and deposition conditions on the resulting microstructure and performance, a systematic investigation of the mechanical properties of thin carbon films using complementary characterization techniques is essential. Mechanical properties such as hardness, elastic modulus, adhesion, and wear resistance are strongly affected by chemical composition and microstructural modifications induced by dopants.
The present work is focused on the study of copper-doped nanocomposite carbon-based thin films prepared by plasma-enhanced chemical vapor deposition (PECVD). A combination of advanced nanoindentation techniques (quasi-static, quasi-static with partial unloading, rapid mechanical mapping - XPM, nanoDMA, etc.) and scratch resistance testing is employed to evaluate the mechanical response of the films. The experimental results are analyzed in order to establish correlations between the chemical composition of the coatings, determined by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX), and their mechanical properties. This approach provides deeper insight into the structure-property relationships of copper-doped carbon thin films and contributes to the development of optimized coatings for targeted industrial and biomedical applications.
Acknowledgement: This research has been supported by the project GA23-06263S, funded by the Czech Science Foundation, LM2023039, funded by MEYS and TN01000038, funded by , funded by the Technology Agency of the Czech Republic.

The intermetallic compound LaNi₅ is a promising material for hydrogen storage. The ternary phase diagram La-Ni-Sn contains phases in which Ni atoms are substituted by Sn atoms resulting in several Sn/Ni different ratios. In order to describe the La(Ni,Sn)5 system by phenomenological CALPHAD modelling, the energy of the completely substituted LaSn5 is needed. As this compound does not exist under ambient conditions, it is difficult to examine experimentally. Therefore, its properties were computed by quantum-mechanical calculations. Density functional theory (DFT) was employed to determine the structural characteristics of LaSn5, along with its electronic structure, energetics and thermodynamic stability as well as its mechanical stability. Our DFT calculations revealed a dramatic volume expansion upon this extreme case of substitution of all Ni atoms by Sn atoms, but the hexagonal structure remains stable without any significant distortions. The electronic calculations also revealed that the electronic density of states has a minimum at the Fermi level, which is in line with the lattice stability.
This study is a part of the project No. CZ.02.01.01/00/22_008/0004631 Materials and technologies for sustainable development within the Jan Amos Komensky Operational Program financed by the European Union and from the state budget of the Czech Republic. DH acknowledges the financial support by the Austrian Federal Ministry for Labour and Economy and the Christian Doppler Research Association. Computational resources were provided by the Ministry of Education, Youth and Sports of the Czech Republic under the Projects e-INFRA CZ (ID:90254) at the IT4Innovations National Supercomputing Center and e-Infrastruktura CZ (e-INFRA LM2018140) at the MetaCentrum as well as CERIT Scientific Cloud, all provided within the program Projects of Large Research, Development and Innovations Infrastructures.

Ternary carbide materials have been proposed for novel technological applications due to the combination of their specific properties as metals and ceramic materials. Among this vast family of compounds, Ti3AlC2 got particular attention because it can be converted through an etching process into the famous MXene Ti3C2, a laminar material with attractive properties for different fields of research and application. In our previous work, we showed the optimization of the synthesis of Ti3AlC2 (temperature gradient, soaking time and temperature, and gas flow) in a highly controlled furnace in an Ar atmosphere. In this work, we present the morphological characterization of the Ti3AlC2 MAX phase produced by an innovative industry-oriented approach. For this purpose, the previously activated Ti/Al/C precursor mixture was subjected to a thermal regime at several soaking temperatures (1150, 1200, 1250, 1300, 1350, 1400 °C), in a Molten salt environment. The methodology allowed us to achieve products with more than 90% by weight of purity, according to the phase composition analysis based on the X-ray diffraction patterns. The scanning electron microscopy confirms the presence of Ti, Al, and C as the majority elements and its analysis allowed us to identify possible secondary products. In addition, the skeletal density of the samples was evaluated by He pycnometry, resulting in all cases in close values to the theoretical one, indicating a successful synthesis process. The slight deviation was attributed to the presence of non-desired phases.

Machine learning tools are becoming increasingly popular when analyzing scientific data, as they can help understanding relations hidden in it. In Scanning Probe Microscopy, they can be particularly useful when treating large datasets coming from novel scanning regimes (e.g. force volume) and from complex samples (e.g. biological). Gwyddion is an open source software for Scanning Probe Microscopy data processing that features many direct and statistical data evaluation tools. In this contribution we review the tools that were added to Gwyddion for machine learning based data classification, clustering and image artifacts estimation, discuss their potential validation routes and compare them to conventional data processing algorithms.

We present the development and experimental validation of a compact, monolithic laser interferometric assembly for ultra-precise two- and three-axis displacement measurement, tailored for integration into modern nanopositioning and nanometrology systems. Designed as an OEM-ready solution, the system targets applications in semiconductor manufacturing, precision coordinate metrology, and ultra-high vacuum (UHV) environments. The assembly features a robust L-shaped monolithic base integrating multiple interferometric channels operated by a single laser source, delivering sub-nanometer periodic error performance in X-Y motion platforms. Its pre-aligned and thermally stable architecture minimizes geometric drift and simplifies system integration, supporting long-term stability and high metrological reliability. Verification based on quadrature phase analysis and comprehensive error metrics confirms sub-nanometer resolution and repeatability, positioning the system as a scalable solution for next-generation nanotechnological instrumentation and motion control.
ACKNOWLEDGEMENTS: Authors acknowledge support from the Technology Agency of the Czech Republic (project TN02000020) and Czech Academy of Sciences (RVO:68081731).

This work presents the development and characterisation of compact interferometric systems designed for monitoring the motion of X-Y positioning stages. The systems use a pair of mutually perpendicular interferometers integrated into a monolithic L-shaped base to track movement in both axes. An optional third interferometer can be added along one of the axes to detect the stage's non-coaxial motion. The compact, monolithic design is optimised for precision coordinate systems and vacuum environment applications.
To evaluate system performance, we introduced a calibration method based on analysing quadrature signals recorded during controlled motion of a reference positioning stage.
The developed interferometric systems achieve sub-nanometer measurement accuracy and repeatability in vacuum conditions. Their design minimises thermal drift and allows straightforward integration into various high-precision applications.

Thermophysical properties at microscale and nanoscale are important when developing heat management materials and structures, needed in the microelectronics industry and related fields. One of the potential parameters to be measured is thermal diffusivity. In this contribution we present a novel dual probe Scanning Thermal Microscopy setup and methodology for addressing measurements of thermal diffusivity using two Scanning Thermal Microscope probes placed at mutual distance between 1 to 60 μm, measuring and analyzing propagation of heat pulses from one probe to another one through the studied sample. Even if the experimental setup and methodology has to be relatively complex to get rid of all the potential error sources, it will be shown that the resulting signals show the expected dependencies and thermal diffusivity can be evaluated from them with a help of a numerical modeling.

One of the essential markers of living cells' condition is the rigidity of their outer membrane. Therefore, cell microrheology is a promising source of information about cells and their well-being. One of the powerful techniques in cell microrheology is atomic force microscopy (AFM). Thanks to force-distance curves measured by AFM, we can obtain information about the rigidity of the cell, respectively, about its Young's modulus. Unfortunately, we can not measure Young's modulus directly, but we can determine it by fitting the force-distance curve with an appropriate model whose choice depends on the sample's shape and the AFM tip's shape. For curved surfaces and rounded AFM cantilever tips, it is relevant to use the Hertz model, and for flat surfaces and a cone cantilever tip, it is suitable to use the Sneddon model. Therefore, we used these two models to analyse the behaviour of the cell membrane after the phagocytosis of nanoparticles. The problem of choosing between the two models is solved by comparing the residuals and errors of fitting both models to the data.

Scanning Thermal Microscopy (SThM) is a method for determination of thermal conductivity of bulk materials, thin films or nanoparticles. In order to switch from qualitative mapping to quantitative measurement, a calibration procedure based on measurement of a series of samples with known conductivities and fitting the data with some model of the microscope response can be used to evaluate data on an unknown sample. The calibration procedure assumes, however, that all samples are flat showing minimal roughness.
In this contribution we show that even battery electrode materials exhibiting large roughness can be analyzed. We used Scanning Electron Microscopy to image nickel manganese cobalt oxide cathode material and to assess its local chemical composition. Based on this information, SThM was used to measure local thermal conductivity on top flat areas of measured particles. We found that thermal conductivities were in the range from 0.237 to 0.436 W/(m*K).

Scanning Probe Microscopy (SPM) is a key technique for nanoscale surface characterization, offering both imaging and quantitative analysis. Its applications in materials science, semiconductor technology, and nanobiology demand reliable measurements, which depend on rigorous calibration.
The objective of the project was to fabricate nanoscale patterns that can serve as calibration standards in SPM techniques. To develop calibration standards, silicon micromachining was employed. Structures produced with this method exhibit high dimensional stability over time and can be easily cleaned if contaminated. This approach focuses on defining a highly repeatable and precise pattern across a large area, which enhances the utility of these standards in practical applications. Two groups of calibration standards were designed, distinguished by their critical dimensions and spacing.
The first group, with a critical dimension of 0.25 µm (HP), was fabricated using electron-beam lithography. The second group, with a 1 µm (HP) dimension, was produced through projection lithography. In both cases, the periodic patterns extend across areas of 3 mm × 3 mm. This large-scale periodicity also allows use in scanning tunnelling microscopy (STM), where navigation and localization are particularly challenging. Each structure includes an identifying label in addition to the central periodic pattern.
The calibration standards were fabricated on 6-inch silicon wafers with (100) crystallographic orientation and n-type conductivity. Subsequent substrate preparation steps varied depending on the design and lithographic technique applied.
The project is co-financed from the state budget by the Minister of Education and Science under the Polish Metrology II program (registration number PM-II/SP/0044/2024/02).

We present a metrological analysis of newly fabricated silicon nanostructured standards, which, together with the developed procedures, are intended to be routine calibration standards for scanning probe microscopy (SPM). The patterns were produced using electron-beam lithography and projection photolithography techniques at Łukasiewicz-Institute of Microelectronics and Photonics (IMIF) in Piaseczno. Measurements of the patterns were performed at Jan Kochanowski University (UJK) in Kielce, using a SPECS Aarhus 150 scanning tunneling microscope, and Marie Curie-Skłodowska University (UMCS) in Lublin, using Bruker/Veeco NanoScope V atomic force microscope. The instruments were calibrated with Au(111) crystal (MaTecK) and certified commercial standards (NT-MDT TGZ1/TGQ1 amd Ted Pella TGZ-20/TG3D-3000/20), respectively.
The measurement process of the produced patterns included the following key steps: sample preparation, instrument stabilization, selection of measurement parameters and image analysis. The primary goal of the measurements was to verify key metrological parameters of the patterns: the size of the nanostructures and their periodicity. Analysis of the acquired images took into account factors such as scanner errors, tip shape, and the use of various software filters. Preliminary results indicate that the patterns meet the requirements of calibration standards used in SPM techniques. Final results, along with statistical analysis, will be published after the measurements are completed.
Currently, interlaboratory comparisons are underway between UJK, UMCS, and the Central Office of Measures, where measurements of the produced patterns will be performed using the SIOS nanopositioning and nanomeasuring machine (NMM-1). These will allow for quantification of the accuracy of the produced patterns, demonstration of their consistency with measurements of other standards, and assessment of the long-term stability of the height and horizontal scale calibration in SPM techniques.
The project is co-financed from the state budget by the Minister of Education and Science under the Polish Metrology II program (registration number PM-II/SP/0044/2024/02).

Nanoindentation is widely used to determine the mechanical properties of materials at the nanoscale, with the accuracy of the method strongly depending on the correct determination of the indenter area function. Typically in nanoindentation, reference samples or atomic force microscopy (AFM) are employed to establish this function. Particular challenges arise from the fitting of the area function and from the question of how to reliably perform AFM characterization of AFM tips themselves. We discuss these issues and outline potential strategies to improve the robustness and transferability of indentation data.

Surface-enhanced Raman scattering (SERS) spectroscopy is a highly sensitive, important non-contact analytical technique valued for its ability to provide unique molecular fingerprints. While traditional SERS platforms rely on plasmonic metal nanostructures, there is a growing interest in developing alternative, non-plasmonic SERS-active materials. Among them, conducting polymers, such as quaterthiophenes or thiophenes, are highly promising candidates due to their cost-effectiveness, flexibility, and easy of processability.
This study explores the SERS performance of spin-coated and thermally cured poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films. We demonstrate that the SERS activity of these films is directly linked to their electrical conductivity. When optimized, the PEDOT:PSS platform can detect methylene blue, a model molecule, with high spectral reproducibility and a detection limit as low as 2×10−8 M. In addition, we demonstrate that placing a highly reflective silver film beneath the PEDOT:PSS layer further amplifies the SERS signal by a factor of five, providing a simple yet effective strategy for signal enhancement. This research thus highlights the potential of PEDOT:PSS as a viable and robust non-plasmonic SERS substrate, suggesting its suitability for broader application in analytical chemistry.
ACKNOWLEDGEMENTS: The authors thank the Czech Science Foundation (grant No. 24-12197S) for financial support.