High sensitivity, low-cost, and disposability: A novel screen-printed electrode developed for direct electrochemical detection of the antibiotic ceftriaxone.

This study describes the development of a novel disposable and low-cost electrochemical platform for detecting the antibiotic ceftriaxone. The screen-printed electrode has been modified with a novel hybrid nanostructure containing silicon oxide (SiO), zirconium oxide (ZrO), and nitrogen-doped carbon quantum dots (Cdot-N). Different techniques like Fourier-transform infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy characterized the hybrid nanostructure used in the sensor surface modifier material.

Phosphotungstic acid impregnated niobium coated superparamagnetic iron oxide nanoparticles as recyclable catalyst for selective isomerization of terpenes.

Conversion efficiency as high as 80-100% and 50% selectivity for camphene and limonene was achieved with low production of polymeric byproducts (18-28%), easy recovery with a magnet and reuse for up to five cycles maintaining similar activity and distribution of products, using a new magnetically recyclable catalyst based on niobium oxide coated on superparamagnetic iron oxide nanoparticles (SPION) impregnated with phosphotungstic acid (HPW). The catalyst was demonstrated to be effective in the selective conversion of alpha and beta-pinenes into valuable terpenes, under ultrasonic probe activation and with toluene as solvent. A unique synergic effect between the components generating more active and selective catalytic sites was demonstrated, indicating that the SPION covered with 30 wt% of NbO gives the best performance when impregnated with HPW as co-catalyst.

2-[(4-Chloro-phen-yl)selan-yl]-3,4-di-hydro-2-benzo[]chromene-5,6-dione: crystal structure and Hirshfeld analysis.

The title organoselenium compound, CHClOSe {systematic name: 2-[(4-chloro-phen-yl)selan-yl]-2,3,4,5,6-naphtho-[1,2-]pyran-5,6-dione}, has the substituted 2-pyranyl ring in a half-chair conformation with the methyl-ene-C atom bound to the methine-C atom being the flap atom. The dihedral angle between the two aromatic regions of the mol-ecule is 9.96 (9)° and indicates a step-like conformation.