The development of an electrochemical immunosensor utilizing chicken IgY anti-spike antibody for the detection of SARS-CoV-2.

This paper introduces a novel approach for detecting the SARS-CoV-2 recombinant spike protein combining a label free electrochemical impedimetric immunosensor with the use of purified chicken IgY antibodies. The sensor employs three electrodes and is functionalized with an anti-S IgY antibody, ELISA and immunoblot assays confirmed the positive response of chicken immunized with SARS-CoV2 S antigen. The developed immunosensor is effective in detecting SARS-CoV-2 in nasopharyngeal clinical samples from suspected cases.

Unveiling the Impact of Drying Methods on Phytochemical Composition and Antioxidant Activity of .

Different drying techniques may alter the chemical composition of plant extracts and consequently affect their bioactivity potential. The current study was designed to reveal the effect of four different drying methods on the phytochemical composition and antioxidant activity of hydrodistilled essential oil (HD-EO) and methanolic (APM) extract obtained from the aerial part of from Jordan. Aerial parts of in their fresh (FR) form and after drying in shade (ShD), sun (SD), oven at 40 °C (O40D) and 60 °C (O60D), in addition to microwave (MWD), were used to extract their essential oils by hydrodistillation and to prepare the different methanolic extracts (APM).

Binary and Ternary Complexes of Cucurbit[8]uril with Tryptophan, Phenylalanine, and Tyrosine: A Computational Study.

Selective binding of amino acids, peptides, and proteins by synthetic molecules and elucidation of the geometry and dynamics of the resulting complexes and their strengths are active areas of contemporary research. In recent work, we analyzed via molecular dynamics (MD) simulations the complexes formed between cucurbit[7]uril (CB7) and three aromatic amino acids: tryptophan (W), phenylalanine (F), and tyrosine (Y). Herein, we continue this line of research by performing MD simulations lasting 100 ns to investigate the formation, stabilities, binding modes, dynamics, and specific host-guest noncovalent interactions contributing to the formation of the binary (1:1) and ternary (2:1) complexes in aqueous solution between W, F, and Y amino acids and cucurbit[8]uril (CB8).

Au-to-Ag coordinate-covalent bonding and other supramolecular interactions with covalent bonding strength.

An efficient strategy for designing charge-transfer complexes using coinage metal cyclic trinuclear complexes (CTCs) is described herein. Due to opposite quadrupolar electrostatic contributions from metal ions and ligand substituents, [Au(μ-Pz-(i-CH))]·[Ag(μ-Tz-(-CF))] (Pz = pyrazolate, Tz = triazolate) has been obtained and its structure verified by single crystal X-ray diffraction - representing the 1 crystallographically-verified stacked adduct of monovalent coinage metal CTCs. Abundant supramolecular interactions with aggregate covalent bonding strength arise from a combination of M-M' (Au → Ag), metal-π, π-π interactions and hydrogen bonding in this charge-transfer complex, according to density functional theory analyses, yielding a computed binding energy of 66 kcal mol between the two trimer moieties - a large value for intermolecular interactions between adjacent d centres (nearly doubling the value for a recently-claimed Au(i) → Cu(i) polar-covalent bond: , 2017, , E5042) - which becomes 87 kcal mol with benzene stacking.

Cupriphication of gold to sensitize d-d metal-metal bonds and near-unity phosphorescence quantum yields.

Outer-shell s/p orbital mixing with d orbitals and symmetry reduction upon cupriphication of cyclic trinuclear trigonal-planar gold(I) complexes are found to sensitize ground-state Cu(I)-Au(I) covalent bonds and near-unity phosphorescence quantum yields. Heterobimetallic AuCu {[Au(μ-C,N-EtIm)Cu(µ-3,5-(CF)Pz)], (4a)}, AuCu {[Au(μ-C,N-BzIm)Cu(µ-3,5-(CF)Pz)], (1) and [Au(μ-C,N-MeIm)Cu(µ-3,5-(CF)Pz)], (3a)}, AuCu {[Au(μ-C,N-MeIm)Cu(µ-3,5-(CF)Pz)], (3b) and [Au(μ-C,N-EtIm)Cu(µ-3,5-(CF)Pz)], (4b)} and stacked Au/Cu {[Au(μ-C,N-BzIm)][Cu(µ-3,5-(CF)Pz)], (2)} form upon reacting Au {[Au(μ-C,N-(N-R)Im)] ((N-R)Im = imidazolate; R = benzyl/methyl/ethyl = BzIm/MeIm/EtIm)} with Cu {[Cu(μ-3,5-(CF)Pz)] (3,5-(CF)Pz = 3,5-bis(trifluoromethyl)pyrazolate)}. The crystal structures of 1 and 3a reveal stair-step infinite chains whereby adjacent dimer-of-trimer units are noncovalently packed via two Au(I)⋯Cu(I) metallophilic interactions, whereas 4a exhibits a hexanuclear cluster structure wherein two monomer-of-trimer units are linked by a genuine d-d polar-covalent bond with ligand-unassisted Cu(I)-Au(I) distances of 2.

Simultaneous electron transfer from free and intercalated 4-benzoylpyridinium cations in cucurbit[7]uril.

N-Substituted 4-benzoylpyridinium monocations form stable host-guest complexes with cucurbit[7]uril (CB[7]) in DMSO (K(eq) approximately 0.6-1.9 x 10(3) M(-1)).

Control of the ketone to gem-diol equilibrium by host-guest interactions.

In water, N-methyl-4-(p-substituted benzoyl)pyridinium cations, BP-X, exist in equilibrium with their hydrated forms (gem-diols), whose concentrations depend on the para substituent (-X). In the presence of cucurbit[7]uril (CB[7]), the benzoyl group shows a preference for the CB[7] cavity, and the ketone to gem-diol equilibrium is shifted toward the keto form, meaning that the stabilization realized through hydrophobic interactions of the benzoyl group in the CB[7] cavity exceeds the hydrogen-bonding stabilization of the gem-diols in the aqueous environment.

Structural characterization of new Cd(2+) fluorescent sensor based on lumazine ligand: AM1 and ab initio studies.

6-Thienyllumazine (TLM) is synthesized as a new fluorescent sensor that is capable of indicating selectively the presence of Cd(2+) ion via a fluorescence signal. Experiment has been performed in the presence of Ni(2+), Co(2+), Cu(2+), Ag(+), Mn(2+), Hg(2+), Zn(2+), Pb(2+), and Mg(2+) metal ions in aqueous solutions. The product was characterized by elemental analysis, mass, and NMR spectra.

Redox-active star molecules incorporating the 4-benzoylpyridinium cation: implications for the charge transfer efficiency along branches vs across the perimeter in dendrimers.

We report the redox properties of four star systems incorporating the 4-benzoyl-N-alkylpyridinium cation; the redox potential varies along the branches but remains constant at fixed radii. Bulk electrolysis shows that at a semi-infinite time scale all redox centers are electrochemically accessible. However, voltammetric analysis (cyclic voltammetry and differential pulse voltammetry) shows that only two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV s-1 and as fast as 10 V s-1.

Synthesis and spectroscopic properties of the elusive 3a,9a-diazaperylenium dication.

The 3a,9a-diazaperylenium dication (1) was synthesized for the first time in two steps from p-phenylene diamine. Ab initio calculations show a twisted ground state with a 6.4 degrees tilt between the two quinolizinium building blocks.