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Ligand-free carbynoid-encapsulated gold nanocomposites (Au@Carbynoid NCs) with blue-shifted localized surface plasmon resonance (LSPR) have been synthesized by CO 2 recycling induced by pulsed laser ablation (PLA) of a solid gold target in aqueous solution with NaOH at pH 7.0. High Resolution Transmission Electron Microscopy (HRTEM) images at not destructive acceleration voltage of 80 kV revealed carbynoid nanocrystals around the gold core, associated to the intense bond length alternation (BLA) Raman mode of the carbon atomic wires (CAWs), centered at 2124 cm −1 , observed in the Surface Enhanced Raman Scattering (SERS) spectra. It was verified that interlinking process with sp to sp 2 conversion of the CAWs is induced both by high acceleration voltage in HRTEM and high irradiance of the excitation beam used in SERS measurements. Post synthesis mixing of Pluronic-F127 copolymer with pre-synthesized Au@Carbynoid NCs allows the formation of a fully biocompatible colloidal solution of Au@Carbynoid/Copolymer NCs. SERS investigation highlights that the Raman band of the BLA mode can be used as efficient Raman tag to monitor the functionalization of the NCs with the copolymer. The biocompatibility of the NCs was demonstrated performing a study of cytotoxicity using human skin fibroblasts. As proof of principle, it was demonstrated that the photodynamic activity of the bifunctional Au@Carbynoid/PF127 NCs in the presence of chlorin e6 (Ce6) drug can be enhanced inducing the aggregation state of the colloidal suspension. The stability of the colloidal dispersions of Au@Carbynoid NCs functionalized with Pluronic-F127 is verified after centrifugation in PBS (0.15 mol L −1 NaCl) solutions, confirming the possibility to use the green carbynoid based NCs as drug-carrier in biological applications. [ABSTRACT FROM AUTHOR]

Organic light emitting diodes (OLED) based on poly(3-octylthiophene) (P3OT) were studied by on-line Surface Enhanced Raman Scattering (SERS) experiments. A simultaneous reduction of the emitted power and an increase of the SERS signal was observed above an 8 V bias voltage in the case of ITO/P3OT/Al structures. On-line measurements of the temperature and independent tests with an atomic force microscope, performed on the Al cathode before and after current flow, demonstrated that the observed enhancement of the Raman signal was partly thermal and partly electromagnetic in origin, with clear evidence of cathode roughening induced by current flow. In contrast, analogous tests performed on P3OT-based OLEDs containing a composite Al+Ag cathode showed that the breakdown was related to electrode delamination. [ABSTRACT FROM AUTHOR]

Minimum energy configurations in 2D material-based heterostructures can enable interactions with external chemical species that are not observable for their monolithic counterparts. Density functional theory (DFT) calculations reveal that the binding energy of divalent toxic metal ions of Cd, Pb, and Hg on graphene-gold heterointerfaces is negative, in contrast to the positive value associated with free-standing graphene. The theoretical predictions are confirmed experimentally by Surface Plasmon Resonance (SPR) spectroscopy, where a strong binding affinity is measured for all the heavy metal ions in water. The results indicate the formation of a film of heavy metal ions on the graphene-gold (Gr/Au) heterointerfaces, where the adsorption of the ions follows a Langmuir isotherm model. The highest thermodynamic affinity constant K = 3.1 × 10 7 L mol -1 is observed for Hg 2+ @Gr/Au heterostructures, compared to 1.1 × 10 7 L mol -1 and 8.5 × 10 6 L mol -1 for Pb 2+ @Gr/Au and Cd 2+ @Gr/Au, respectively. In the case of Hg 2+ ions, it was observed a sensitivity of about 0.01°/ppb and a detection limit of 0.7 ppb (∼3 nmol L -1 ). The combined X-ray photoelectron spectroscopy (XPS) and SPR analysis suggests a permanent interaction of all of the HMIs with the Gr/Au heterointerfaces. The correlation between the theoretical and experimental results indicates that the electron transfer from the graphene-gold heterostructures to the heavy metal ions is the key for correct interpretation of the enhanced sensitivity of the SPR sensors in water.

THz radiation has gained great importance due to its potential applications in a wide variety of fields. For this reason, continuous efforts have been made to develop technological tools for use in this versatile band of the electromagnetic spectrum. Here, we propose a reflecting device with long focusing performances in the sub-THz band, using a bimirror device in which the relative angle is mechanically adjusted with the displacement of one of the mirrors. Despite the simplicity of the setup, the performance of this device is satisfactory down to a frequency of 0.1 THz. Theory and experience confirm that the bimirror is capable of focusing 0.1 THz radiation with a 2× magnification of the maximum input intensity while maintaining a longitudinal full width at half maximum (FWHM) of about 6 mm, which is about 12 times the depth of focus of a cylindrical optical element of the same focal length. In the absence of suitable THz equipment, the invariance property of the Fresnel diffraction integral allowed the predicted behavior to be tested in the THz range using conventional equipment operating at visible frequencies.

THz radiation has assumed great importance thanks to the efforts in the development of technological tools used in this versatile band of the electromagnetic spectrum. Here, we propose a reflective biprism device with wavelength-independent long-focusing performances in the THz band by exploiting the high thermo-mechanical deformation of the elastomer polydimethylsiloxane (PDMS). This deformation allows for achieving significant optical path modulations in the THz band and effective focusing. The surface of a PDMS layer is covered with a gold thin film acting as a heater thanks to its absorption of wavelengths below ~500 nm. An invariance property of the Fresnel integral has been exploited to experimentally verify the THz performances of the device with an ordinary visible laser source, finding excellent agreement with the theoretical predictions at 1 and 3 THz. The same property also allowed us to experimentally verify that the reflective biprism focus has a longitudinal extension much greater than that exhibited by a benchmark convex cylindrical mirror with the same optical power. The device is thermo-mechanically stable up to a heating power of 270 mW, although it might be potentially exploited at higher powers with minor degradation of the optical performances.

Background: In the past decades studies on anti-tumoral drugs inhibiting matrix metalloproteinase (MMPs) were disappointing. Recently, we demonstrated that mature endothelial cells (ECs) and endothelial colony forming cells (ECFCs) can switch between invasion modes to cope with challenging environments, performing the "amoeboid angiogenesis" in the absence of proteases activity., Methods: We first set out to investigate by ELISA if the inhibitors of the main protease family involved in angiogenesis were differently expressed during breast cancer progression. We used Marimastat, a broad-spectrum MMP inhibitor, as a means of inducing amoeboid characteristics and studied VEGF role in amoeboid angiogenesis. Thus, we performed invasion and capillary morphogenesis assay, morphological, cell signaling and in vivo mouse studies., Results: Our data showed that TIMP1, TIMP2, alpha2-antiplasmin, PAI-1 and cystatin increase in breast cancer serum of patients with primary cancer and lymph node positive compared to healthy women. In vitro results revealed that the most high-powered protease inhibitors able to induce amoeboid invasion of ECFCs were TIMP1, 2 and 3. Surprisingly, Marimastat promotes ECFC invasion and tubular formation in vitro and in vivo, inducing amoeboid characteristics. We observed that the combination of Marimastat plus VEGF doesn't boost neither cell invasion nor vessel formation capacity. Moreover, inhibition of VEGF activity with Bevacizumab in the presence of Marimastat confirmed that amoeboid angiogenesis is independent from the stimulus of the main vascular growth factor, VEGF., Conclusions: We underline the importance to consider the amoeboid mechanism of endothelial and cancer cell invasion, probably responsible for the failure of synthetic metalloproteinase inhibitors as cancer therapy and tumor resistance to VEGF-targeted therapies, to set-up new drugs to be used in cancer therapy., (© 2023. The Author(s).)

Electronic devices featuring biomimetic behaviour as electronic synapses and neurons have motivated the emergence of a new era in information and humanoid robotics technologies. In the human body, a nociceptor is a unique sensory neuron receptor that is capable of detecting harmful signals, leading to the central nervous system initiating a motor response. Herein, a nickel-doped zinc oxide (NZO)/Au based memristor is fabricated for the first time and characterized for artificial nociceptor application. For this, the introduction of a nickel-doped zinc oxide (NZO) layer between P ++ -Si and Au electrodes is used to eliminate the surface effects of the NZO layer, resulting in improved volatile threshold switching performance. Depending on the intensity, duration, and repetition rate of the external stimuli, this newly created memristor exhibits various critical nociceptive functions, including threshold, relaxation, allodynia, and hyperalgesia. The electron trapping/detrapping to/from the traps in the NZO layer is responsible for these nociceptive properties. This kind of NZO-based device produces a multifunctional nociceptor performance that is essential for applications in artificial intelligence systems, such as neural integrated devices with nanometer-sized features.

The co-precipitation approach was utilized to experimentally synthesize ZnO, Zn 0.96 Gd 0.04 O and Zn 0.96- x Gd 0.04 Co x O (Co = 0, 0.01, 0.03, 0.04) diluted magnetic semiconductor nanotubes. The influence of gadolinium and cobalt doping on the microstructure, morphology, and optical characteristics of ZnO was investigated, and the Gd doping and Co co-doping of the host ZnO was verified by XRD and EDX. The structural investigation revealed that the addition of gadolinium and cobalt to ZnO reduced crystallinity while maintaining the preferred orientation. The SEM study uncovered that the gadolinium and cobalt dopants did not affect the morphology of the produced nanotubes, which is further confirmed through TEM. In the UV-vis spectra, no defect-related absorption peaks were found. By raising the co-doping content, the crystalline phase of the doped samples was enhanced. It was discovered that the dielectric response and the a.c. electrical conductivity display a significant dependent relationship. With the decreasing frequency and increasing Co co-dopant concentration, the ε r and ε '' values decreased. It was also discovered that the ε r , ε '', and a.c. electrical conductivity increased when doping was present. Above room temperature, co-doped ZnO nanotubes exhibited ferromagnetic properties. The ferromagnetic behaviour increased as Gd (0.03) doping increased. Increasing the Co content decreased the ferromagnetic behaviour. It was observed that Zn 0.96- x Gd 0.04 Co x O ( x = 0.03) nanotubes exhibit superior electrical conductivity, magnetic and dielectric characteristics compared to pure ZnO. This high ferromagnetism is typically a result of a magnetic semiconductor that has been diluted. In addition, these nanoparticles are utilized to design spintronic-based applications in the form of thin-films., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Submicron long focusing range beams are gaining attention due to their potential applications, such as in optical manipulation, high-resolution lithography and microscopy. Here, we report on the theoretical and experimental characterization of an elastomeric polydimethylsiloxane/single layer graphene (PDMS/SLG) axicon-like tunable device, able to generate diffraction-resistant submicrometric spots in a pump and probe configuration. The working principle is based on the phase change of an input Gaussian beam induced in the elastomer via the thermo-optical effect, while the heating power is produced by the optical absorption of the SLG. The phase-modified beam is transformed by an objective into a long focus with submicron diameter. Our foci reach an experimental full width at half maximum (FWHM) spot diameter of 0.59 μm at the wavelength of 405 nm, with the FWHM length of the focal line greater than 90 μm. Moreover, the length of the focal line and the diameter of the focus can be easily tuned by varying the pump power. The proposed thermo-optical device can thus be useful for the simple and cheap improvement of the spatial resolution on long focus lines.