The Visible-Light-Driven Activity of Biochar-Doped TiO2 Photocatalysts in β-Blockers Removal from Water

Water is the most important life-giving resource on earth. Nowadays, intensive growth of the world population has resulted in increased water consumption and the production of wastewater. Additionally, the presence of pharmaceuticals in treated conventional wastewater or even in the environment is strictly indicating that present techniques of wastewater treatment are not efficient enough and are not designed to remove such pollutants. Scarce water resources in the world are the main driving force for the innovation of novel techniques of water and wastewater treatment. Photocatalysis, as one of the advanced oxidation processes, enables the transformation of recalcitrant and toxic pollutants into CO₂, water, and inorganic salts. In the present paper, the photocatalytic oxidation of β-blockers-metoprolol and propranolol-are described. For photocatalytic oxidation, novel TiO₂ photocatalysts modified with biochar were used. Photocatalysts were prepared by sol-gel method and the effect of photocatalysts type, presence of inorganic ions, dissolved organic matter, and different water matrix was established. The results indicate that using only the decrease in the tested pollutant concentration is not effective enough in establishing the treatment method's safety. There is a need to use additional testing such as ecotoxicity tests; however, the key parameter is the properly chosen tested organism.

UV-Cured Green Polymers for Biosensorics: Correlation of Operational Parameters of Highly Sensitive Biosensors with Nano-Volumes and Adsorption Properties

The investigated polymeric matrixes consisted of epoxidized linseed oil (ELO), acrylated epoxidized soybean oil (AESO), trimethylolpropane triglycidyl ether (RD1), vanillin dimethacrylate (VDM), triarylsulfonium hexafluorophosphate salts (PI), and 2,2-dimethoxy-2-phenylacetophenone (DMPA). Linseed oil-based (ELO/PI, ELO/10RD1/PI) and soybean oil-based (AESO/VDM, AESO/VDM/DMPA) polymers were obtained by cationic and radical photopolymerization reactions, respectively. In order to improve the cross-linking density of the resulting polymers, 10 mol.% of RD1 was used as a reactive diluent in the cationic photopolymerization of ELO. In parallel, VDM was used as a plasticizer in AESO radical photopolymerization reactions. Positron annihilation lifetime spectroscopy (PALS) was used to characterize vegetable oil-based UV-cured polymers regarding their structural stability in a wide range of temperatures (120-320 K) and humidity. The polymers were used as laccase immobilization matrixes for the construction of amperometric biosensors. A direct dependence of the main operational parameters of the biosensors and microscopical characteristics of polymer matrixes (mostly on the size of free volumes and water content) was established. The biosensors are intended for the detection of trace water pollution with xenobiotics, carcinogenic substances with a very negative impact on human health. These findings will allow better predictions for novel polymers as immobilization matrixes for biosensing or biotechnology applications.

Studies on healthy and neoplastic tissues using positron annihilation lifetime spectroscopy and focused histopathological imaging

Samples of healthy and neoplastic myometrial tissues were investigated using Positron Annihilation Lifetime Spectroscopy (PALS). Meaningful differences between normal and diseased tissues were observed for each patient. The differences were also clearly visible for various kinds of lesions in each patient. The set of lifetimes and intensities obtained from PALS was correlated with the histopathological examinations of the same fragments of tissues. Strong coincidence between PALS parameters and histopathological findings was observed only in the case of a very precise correlation of the investigated area in both techniques. Measurements and discussion presented here were carried out to develop a method for measuring the sub-nanometric structure of human tissues. This kind of investigation, using positron probe, creates an opportunity of a new application in Positron Emission Tomography (PET).