The luminescent properties of epitaxial Cu₂O thin films were studied in 10–300 K temperature range and compared with the luminescent properties of Cu₂O single crystals. Cu₂O thin films were deposited epitaxially via the electrodeposition method on either Cu or Ag substrates at different processing parameters, which determined the epitaxial orientation relationships. Cu₂O (100) and (111) single crystal samples were cut from a crystal rod grown using the floating zone method. Luminescence spectra of thin films contain the same emission bands as single crystals around 720, 810 and 910 nm, characterizing ${\mathrm{V}}_{\mathrm{O}}^{2+}$, ${\mathrm{V}}_{\mathrm{O}}^{+}$ and ${\mathrm{V}}_{\mathrm{Cu}}$ defects, correspondingly. Additional emission bands, whose origin is under discussion, are observed around 650–680 nm, while the exciton features are negligibly small. The relative mutual contribution of the emission bands varies depending on the thin film sample. The existence of the domains of crystallites with different orientations determines the polarization of luminescence. The PL of both Cu₂O thin films and single crystals is characterized by negative thermal quenching in the low-temperature region; the reason of this phenomenon is discussed.

Indium tin oxide (ITO) is a transparent conducting material with exceptional electrical and optical properties, widely used in biosensing and bioelectronics. Functionalization of ITO with linker molecules enables covalent attachment of biomolecules, allowing for dual-mode optical and electrochemical detection. Carbonic anhydrase IX (CA IX), a transmembrane enzyme overexpressed in hypoxic tumors, is a promising biomarker for cancer diagnostics due to its restricted expression in normal tissues. However, conventional detection methods are time-intensive and unsuitable for point-of-care applications. In this study, ITO surfaces were functionalized using silane-based chemistry to immobilize CA IX-specific antibodies, creating a novel biosensing platform. The biosensor utilized a secondary horseradish peroxidase (HRP)-conjugated antibody to catalyze the oxidation of luminol in the presence of hydrogen peroxide, producing a chemiluminescent and electrochemical signal. Characterization of the biosensor via a dual-mode optical and electrochemical approach revealed efficient antibody immobilization. Due to the high variation observed in the optical approach, limit of detection (LOD) experiments were conducted exclusively with electrochemistry, yielding an LOD of 266.4 ng/mL. These findings demonstrate the potential of ITO-based electrochemical biosensors for sensitive and selective CA IX detection, highlighting their applicability in cancer diagnostics and other biomedical fields.

Surface modification is essential in microfluidic applications due to the inherent hydrophobicity of polymers, which can lead to biofouling and reagent denaturation. Despite the development, challenges such as hydrophobic molecule absorption and limitations in scaling are still present. Off-stoichiometry thiol-ene (OSTE) materials have emerged as a promising alternative, offering advantages like rapid prototyping, minimal hydrophobic absorption, and customizable surface chemistries. While the thiol-ene polymerization mechanism is well understood, the fundamental understanding of thiol group binding on OSTE surfaces remains limited. Existing techniques to analyze surface groups lack the capability to confirm the stable presence of thiol groups on the surface. In our study, using Raman and X-ray photoelectron spectroscopy techniques, we investigated a potential method for enhancing the surface properties of OSTE polymer—the attachment of novel linkers to the surface. We have demonstrated our synthesized compound efficiency by binding gold nanoparticles to the OSTE surface. Our findings indicate that chemical reactions involving double bonds with the material surface hold the most potential for effective surface modification for gold binding.

Protein binding efficiency to OSTE increased by approximately 4 orders of magnitude using a novel linker. This linker provides a shelf-stable and simple method for protein attachment to OSTE surfaces.

Luminescent properties of epitaxial Cu2O thin films were studied in 10-300 K temperature range and compared with luminescent properties of Cu2O single crystals. Cu2O thin films were deposited epitaxially by the electrodeposition method on either Cu or Ag substrates at different processing parameters, which determined the epitaxial orientation relationships and encapsulated surface. Cu2O (100) and (111) single crystal samples were cut from a crystal rod grown by the floating zone method. Luminescence spectra of thin films contain the same emission bands as single crystals around 720, 810 and 910 nm, characterizing VO2+, VO+ and VCu defects, correspondingly. Additional emission bands, whose origin is under discussion, are observed around 650-680 nm, while the exciton features are negligibly small. The relative mutual contribution of the emission bands varies depending on the particular thin film sample. Existence of the domains of crystallites with different orientation determines the polarization of luminescence. PL of both Cu2O thin films and single crystals is characterized with negative thermal quenching in the low temperature region, the reason of this phenomenon is discussed.