Electrochemically grafted gallic acid-chitosan: a metal-free redox platform for regiospecific oligopeptide-viral spike protein interaction.

Electrochemical grafting of gallic acid with chitosan (EgGC) voltammetrically deposited on a multitude of substrates exhibiting reversible oxidoreduction suitable for sensor construction is reported. A bioreceptor customized from the fragment antigen binding region of SARS-CoV-2 neutralizing antibodies immobilized on an EgGC matrix supported the selective/specific electrochemical signal transduction with respect to different viral loads (femtogram level) of SARS-CoV-2.

β-Cyclodextrin-Tethered Butein, a Greener Redox-Active Biomaterial for Electrochemical Enzymatic Sensing of Sialic Acid.

Biocompatible, industrially scalable, and opto/electrochemically active biomaterials are promising for biosensor platform design and application. Herein, cyclic oligosaccharide, β-cyclodextrin (BCD), is conjugated with Butein, a chalcone-type polyphenol, via dehydration reaction of the hydroxyl groups of BCD and the benzoyl ring of Butein. Functional group changes in the conjugated BCD-Butein were comprehensively studied using UV-visible absorbance, Fourier transform-infrared, and X-ray photoelectron spectroscopic techniques.

Buteinylated-hafnium oxide bionanoparticles for electrochemical sensing of wogonin.

Hybridizing biomolecules with metal oxide nanostructures possessing inherent optical emission and electrochemical functionality is advantageous for external mediator-free analytical applications. This work demonstrates the ultrasonochemical synthesis of hafnium oxide (HfO) nanoparticles and their combination with butein, a chalcone type polyphenol, for the direct electrochemical detection of active herbaceuticals. The underlying hybridization chemistry between HfO and butein within the bio-nano interface is comprehensively investigated using ultraviolet diffuse reflectance, X-ray diffraction, Fourier-transform infrared, and X-ray photoelectron spectroscopic techniques.

Bioadhesive Gauze Embedded with Chitosan-Butein Bioconjugate: A Redox-Active pH Sensor Platform.

With the ever-growing global wound care market, demand for robust redox-active healthcare material is obvious for the construction of wearable sensor platforms. Surface reactive functional group-rich material like chitosan holds huge potential for electrochemical biosensor application. Herein, a metal-free redox-active chitosan-butein (CSB) bioconjugate is processed into epidermal bioadhesive electrode material useful for pH sensors promising toward wound site analysis.

Peptide-based direct electrochemical detection of receptor binding domains of SARS-CoV-2 spike protein in pristine samples.

RNA isolation and amplification-free user-friendly detection of SARS-CoV-2 is the need of hour especially at resource limited settings. Herein, we devised the peptides of human angiotensin converting enzyme-2 (ACE-2) as bioreceptor at electrode interface for selective targeting of receptor binding domains (RBD) of SARS-CoV-2 spike protein (SP). Disposable carbon-screen printed electrode modified with methylene blue (MB) electroadsorbed graphene oxide (GO) has been constructed as cost-efficient and scalable platform for ACE-2 peptide-based SARS-CoV-2 detection.

Chitosan grafted butein: A metal-free transducer for electrochemical genosensing of exosomal CD24.

Metal-free cost-efficient biocompatible molecules are beneficial for opto-electrochemical bioassays. Herein, chitosan (CS) conjugated butein is prepared via graft polymerization. Structural integrity between radical active sites of CS and its probable conjugation routes with reactive OH group of butein during grafting were comprehensively studied using optical absorbance/emission property, NMR, FT-IR and XPS analysis.

Unusual Methylenediolate Bridged Hexanuclear Ruthenium(III) Complexes: Syntheses and Their Application.

Three structurally analogous hexanuclear ruthenium(III) complexes were isolated with the general molecular formula of [Ru(O)(μ-η-η-CHO)( t-BuCO)(L)] where L = pyridine (1) or 4-dimethylamino pyridine (DMAP; 2) or 4-cyanopyridine (3). Complexes 1 and 3 were solved in the tetragonal I4̅c2 and P422 space group, respectively, while 2 crystallized in the monoclinic system with P2 /c space group. In all three complexes, two oxo-centered Ru(III) triangles were bridged by a unique and a rare methylenediolate (CHO)) ligand.