SPR and Double Resonance LPG Biosensors for BabA Antigen Detection.

Given the medical and social significance of infection, timely and reliable diagnosis of the disease is required. The traditional invasive and non-invasive conventional diagnostic techniques have several limitations. Recently, opportunities for new diagnostic methods have appeared based on the recent advance in the study of outer membrane proteins and their identified receptors.

A Spectrally Interrogated Polarimetric Optical Fiber Sensor for Current Measurement with Temperature Correction.

We report on a study of the temperature dependence of the response of a BSO crystal based polarimetric current sensor with spectral interrogation. Two possible interrogation schemes are discussed. The spectral dependence of the optical rotation along the crystal caused by temperature and current changes is investigated, and approximate dependences for the sensitivities to current and temperature are derived.

Electrostatic interactions - key determinants of the metal selectivity in La and Ca binding proteins.

Nearly half of all known proteins contain metal co-factors. In the course of evolution two dozen metal cations (mostly monovalent and divalent species) have been selected to participate in processes of vital importance for living organisms. Trivalent metal cations have also been selected, although to a lesser extent as compared with their mono- and divalent counterparts.

Binding of SARS-CoV-2 Structural Proteins to Hemoglobin and Myoglobin Studied by SPR and DR LPG.

One of the first clinical observations related to COVID-19 identified hematological dysfunctions. These were explained by theoretical modeling, which predicted that motifs from SARS-CoV-2 structural proteins could bind to porphyrin. At present, there is very little experimental data that could provide reliable information about possible interactions.

Capabilities of Double-Resonance LPG and SPR Methods for Hypersensitive Detection of SARS-CoV-2 Structural Proteins: A Comparative Study.

The danger of the emergence of new viral diseases and their rapid spread demands apparatuses for continuous rapid monitoring in real time. This requires the creation of new bioanalytical methods that overcome the shortcomings of existing ones and are applicable for point-of-care diagnostics. For this purpose, a variety of biosensors have been developed and tested in proof-of-concept studies, but none of them have been introduced for commercial use so far.

Host-guest complexation of cucurbit[7]uril and cucurbit[8]uril with the antimuscarinic drugs tropicamide and atropine.

Cucurbiturils are useful excipients in eye drop formulations: they can increase the water solubility of the drug, enhance drug absorption into the eye, improve aqueous stability and reduce local irritation. Effective and safe drug delivery is, however, a challenge and the information on the host (CBs)/guest (tropicamide and atropine) interactions can help improving the existing treatments and develop novel therapies not limited only to eye diseases/conditions. Since this carrier system can easily modify the properties of the drug and ensure its delivery at the targeted ocular tissue, further insight into the intimate mechanism of the host-guest recognition is crucial.

Competition between Ag and Ni in nickel enzymes: Implications for the Ag antibacterial activity.

Silver's antimicrobial properties have been known for centuries, but exactly how it kills bacteria is still a mystery. Information on the competition between the native Ni and abiogenic Ag cations in bacterial systems is also critically lacking. For example, urease, a famous nickel-containing enzyme that hydrolyzes urea into carbon dioxide and ammonia (a key step in the biogeochemical nitrogen cycle on Earth), is inhibited by Ag cations, but the molecular mechanism of silver's action is poorly understood.

Complexation of trivalent metal cations (Al, Ga, In, La, Lu) to cucurbiturils: a DFT/SMD evaluation of the key factors governing the host-guest recognition.

Cucurbiturils (CBs), the pumpkin-shaped macrocycles, are suitable hosts for an array of neutral and cationic species. A plethora of host-guest complexes between CBs and a variety of guest molecules has been studied. However, much remains unknown, even in the complexation of very simple guests such as metal cations.

SPR-Based Kinetic Analysis of the Early Stages of Infection in Cells Infected with Human Coronavirus and Treated with Hydroxychloroquine.

Cell-based assays are a valuable tool for examination of virus-host cell interactions and drug discovery processes, allowing for a more physiological setting compared to biochemical assays. Despite the fact that cell-based SPR assays are label-free and thus provide all the associated benefits, they have never been used to study viral growth kinetics and to predict drug antiviral response in cells. In this study, we prove the concept that the cell-based SPR assay can be applied in the kinetic analysis of the early stages of viral infection of cells and the antiviral drug activity in the infected cells.

Molecular insights into the interaction of angiotensin I-converting enzyme (ACE) inhibitors and HEXXH motif.

Nutraceuticals and functional foods garner a lot of attention as potential alternative therapies for treatment of (pre)hypertension. Food-derived proteins release large variety of bioactive peptides which are similar in structure to peptide sequences acting in the organism and therefore can modulate their physiological functions. Val-Pro-Pro (VPP) is a milk-derived tripeptide with assumed mild inhibitory activity against angiotensin-converting enzyme (ACE).

Competition between abiogenic and biogenic metal cations in biological systems: Mechanisms of gallium's anticancer and antibacterial effect.

Metal cations are key players in a plethora of essential biological processes. Over the course of evolution specific biological functions have been bestowed upon two dozen of (biogenic) metal species, some of the most frequently found being sodium, potassium, magnesium, calcium, zinc, manganese, iron, and copper. On the other hand, there is a group of less studied abiogenic metals like lithium, strontium and gallium that possess not known functions in living organisms, but, by mimicking the native ions and/or competing with them for binding to key metalloenzymes, may exert beneficial effect on humans in particular medical conditions.

Complexation of biologically essential (mono- and divalent) metal cations to cucurbiturils: a DFT/SMD evaluation of the key factors governing the host-guest recognition.

Supramolecular complexes based on classical synthetic macrocyclic host molecules such as cyclodextrins and calixarenes have received much attention recently due to their broad applications as biological and chemical sensors, bioimaging agents, drug delivery carriers, light-emitting materials, Cucurbit[]urils comprise another group of cavitands known for their high affinity for various guest molecules. Nonetheless, some aspects of their coordination chemistry remain enigmatic. Although they are recognized as potential biomimetic scaffolds, they are still not tested as metalloenzyme models and not much is known about their metal-binding properties.

Optical Sensing of Humidity Using Polymer Top-Covered Bragg Stacks and Polymer/Metal Thin Film Structures.

Thin films with nanometer thicknesses in the range 100-400 nm are prepared from double hydrophilic copolymers of complex branched structures containing poly(-dimethyl acrylamide) and poly(ethylene oxide) blocks and are used as humidity sensitive media. Instead of using glass or opaque wafer for substrates, polymer thin films are deposited on Bragg stacks and thin (30 nm) sputtered Au-Pd films thus bringing color for the colorless polymer/glass system and enabling transmittance measurements for humidity sensing. All samples are characterized by transmittance measurements at different humidity levels in the range from 5% to 90% relative humidity.

Vapor responsive one-dimensional photonic crystals from zeolite nanoparticles and metal oxide films for optical sensing.

The preparation of responsive multilayered structures with quarter-wave design based on layer-by-layer deposition of sol-gel derived Nb(2)O(5) films and spin-coated MEL type zeolite is demonstrated. The refractive indices (n) and thicknesses (d) of the layers are determined using non-linear curve fitting of the measured reflectance spectra. Besides, the surface and cross-sectional features of the multilayered structures are characterized by scanning electron microscopy (SEM).

Nanosized thin SnO₂ layers doped with Te and TeO₂ as room temperature humidity sensors.

In this paper the humidity sensing properties of layers prepared by a new method for obtaining doped tin oxide are studied. Different techniques-SEM, EDS in SEM, TEM, SAED, AES and electrical measurements-are used for detailed characterization of the thin layers. The as-deposited layers are amorphous with great specific area and low density.