The irradiance of ultraviolet (UV) radiation is a physical parameter that significantly influences biological molecules by affecting their molecular structure. The influence of UV radiation on nanoparticles has not been investigated much. In this work, the ability of cadmium telluride quantum dots (CdTe QDs) to respond to natural UV radiation was examined. The average size of the yellow QDs was 4 nm, and the sizes of green, red and orange QDs were 2 nm. Quantum yield of green CdTe QDs-MSA (mercaptosuccinic acid)-A, yellow CdTe QDs-MSA-B, orange CdTe QDs-MSA-C and red CdTe QDs-MSA-D were 23.0%, 16.0%, 18.0% and 7.0%, respectively. Green, yellow, orange and red CdTe QDs were replaced every day and exposed to daily UV radiation for 12 h for seven consecutive days in summer with UV index signal integration ranging from 1894 to 2970. The rising dose of UV radiation led to the release of cadmium ions and the change in the size of individual QDs. The shifts were evident in absorption signals (shifts of the absorbance maxima of individual CdTe QDs-MSA were in the range of 6–79 nm), sulfhydryl (SH)-group signals (after UV exposure, the largest changes in the differential signal of the SH groups were observed in the orange, green, and yellow QDs, while in red QDs, there were almost no changes), fluorescence, and electrochemical signals. Yellow, orange and green QDs showed a stronger response to UV radiation than red ones.

In this work, we focused on the green synthesis of silver nanoparticles (AgNPs). In the green synthesis, plant extracts are used as reducing agents. AgNPs contain surface-bound biomolecules from the used plant extract. We used an aqueous extract from sage (Salvia officinalis). This plant is known for its high content of secondary metabolites with excellent antibacterial activity. Antibacterial activity of AgNPs prepared by green synthesis was investigated. Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli were selected for testing. Methods such as agar diffusion assay and inhibition of bacterial growth curves were used. Minimum inhibitory concentrations (MICE. coli = 250 µg/mL; MICS. aureus = 50 µg/mL) were determined. The radiuses of inhibition zones were about 1.5 cm in both bacterial strains. AgNPs prepared by this method can play an important role in dealing with the problem of bacterial resistance. Bacteria develop resistance not only to typical antibiotics. Bacterial cells are also able to eliminate the effect of AgNPs. By modifying their surface with antibacterial molecules, resistance can be effectively combatted.

Sarcosine oxidase (SOX) is a flavoprotein and cleaves sarcosine to form hydrogen peroxide, glycine and formaldehyde. Sarcosine is commonly found in muscle, tissues, toothpaste and food supplements. Increased amounts have been found in patients with prostate cancer. SOX is an enzyme suitable for the enzymatic determination of sarcosine. Biotechnological applications require increased stability of used enzymes. In our study, we focused on temperature (5, 15, 20, 30, 35, 40, 50 and 60 °C) and pH-dependent changes (pH 5,

Prostate cancer is the most common malignant tumor in men, whose incidence is significantly different geographically and increases with age. For rapid diagnostics, new tumor markers with higher prognostic relevance are still being sought. A very promising candidate molecule is the amino acid sarcosine. The aim of this work was to design a highly sensitive photometric detection system for the sarcosine determination. An original methodology for determining the amino acid sarcosine using Trinder's reaction with sarcosine oxidase and Amplex Red fluorophore has been proposed. To improve the enzymatic reaction sarcosine oxidase and horseradish peroxidase were immobilised on superparamagnetic irone oxide nanoparticles (SPIONs). Absorbance dependence on sarcosine concentration read off at the wavelength of 572 nm was linear over a total range of 0 -1000 μM (r ≥ 0.99) with limit of detection (LOD) of 2 μM and limit of quantification (LOQ) of 6 μM. The suggested procedure allows to analyze the content of sarcosine in real urine specimens. The proposed method is capable of detecting sarcosine at micromolar concentrations.

3D printing is a modern and widely used technology that has reached virtually all sectors of human activity, from the automotive industry to medical fields. Silver nanoparticles (AgNPs) have considerable industrial potential and are intensively studied regarding their antibacterial capability. Using green synthesis, the nanoparticle surface can be coated with molecules that exhibit biologically significant properties. By combining 3D printing technology and antibacterial activity of AgNPs, a unique antibacterial material can be prepared. The aim of this work was to modify the printing filament with AgNPs, to prepare the antibacterial material by 3D printing and to test the antibacterial activity of the prepared material using the JIS (Japanese industrial standards) L 1902 method. Such material can be used in hospital facilities to adjust various devices to prevent nosocomial infections.