Enantioselective, Chirally Templated Sol−Gel Thin Films

Enantioselective surfactant-templated thin films were fabricated through the sol−gel (SG) process. The enantioselectivity is general in the sense that it discriminates between pairs of enantiomers not used for the imprinting process. The chiral cationic surfactant (−)-N-dodecyl-N-methylephedrinium bromide (1) was used as the surfactant template, and after its extraction chiral domains were created. The chiral discriminative feature of these films was examined by challenging with pure enantiomer solutions for rebinding. Selective adsorption was shown using (R)- and (S)-propranolol, (R)-2 and (S)-2, respectively, and (R)- and (S)-2,2,2-trifluoro-1-(9-anthryl)ethanol, (R)-3 and (S)-3, respectively, as the chiral probes. The selective adsorption was measured by fluorescence analysis, and the chiral selectivity factors were found to be 1.6 for 2 and 2.25 for 3. In both cases, (R)-enantiomer was adsorbed preferably. The resulting material was characterized by transmission electron microscopy, by diffraction, and by surface area measurements, and was found to be semicrystalline with short-range ordered domains (50 Å) of hexagonal symmetry

Highly Stable Lyophilized Homogeneous Bead-Based Immunoassays for On-Site Detection of Bio Warfare Agents from Complex Matrices

This study shows the development of dry, highly stable immunoassays for the detection of bio warfare agents in complex matrices. Thermal stability was achieved by the lyophilization of the complete, homogeneous, bead-based immunoassay in a special stabilizing buffer, resulting in a ready-to-use, simple assay, which exhibited long shelf and high-temperature endurance (up to 1 week at 100 °C). The developed methodology was successfully implemented for the preservation of time-resolved fluorescence, Alexa-fluorophores, and horse radish peroxidase-based bead assays, enabling multiplexed detection. The multiplexed assay was successfully implemented for the detection of Bacillus anthracis, botulinum B, and tularemia in complex matrices

Stimuli Response of Eu³⁺-Based Metallo-Supramolecular Polymers toward Pharmaceutical Amines

Metallo-supramolecular polymers offer a highly controllable platform for sensing. Their modular characteristics obtained by the ability of varying both building blocks, the metal ion and the organic ligand, provide tunability of their optical and chemical properties. Specifically, polymers based on lanthanide ions and conjugated aromatic ligands exhibit enhanced luminescence properties that can be altered by external stimulation. Herein, using europium-based polymers, we demonstrate the ability to detect different pharmaceutical amines, including in complex biological media, based on their luminescence quenching efficiency as a result of their polymer dissociation capacity. A combination of absorption, luminescence, and NMR measurements reveals combined static and dynamic quenching mechanisms that enable selective sensing of strong basic amines with high pKa values