ABSTRACT
This work reports the heterogenization of Rose Bengal dye on simple cellulose paper sheets (Cell-RB) through copper-catalyzed azide-alkyne click ligation. The photocatalytic properties of Cell-RB under green LED irradiation were evaluated in a series of dehydrogenative transformations for the functionalization of N-aryltetrahydroisoquinolines and quinoxalin-2(1H)-ones. The excellent photocatalytic activities observed, associated to the ease of recovery with simple tweezers, highlight the strong assets of Cell-RB with respect to traditional homogeneous organic photocatalysts.
Subject(s)
Cellulose , Rose Bengal , Copper , LightABSTRACT
We developed a chemical method to covalently functionalize cellulose nanofibers and cellulose paper with mannoside ligands displaying a strong affinity for the FimH adhesin from pathogenic E. coli strains. Mannose-grafted cellulose proved efficient to selectively bind FimH lectin and discriminate pathogenic E. coli strains from non-pathogenic ones. These modified papers are valuable tools for diagnosing infections promoted by E. coli, such as cystitis or inflammatory bowel diseases, and the concept may be applicable to other life-threatening pathogens.
Subject(s)
Cellulose/chemistry , Escherichia coli K12/isolation & purification , Mannans/chemistry , Nanofibers/chemistry , Adhesins, Escherichia coli/metabolism , Bacterial Adhesion/drug effects , Bacterial Typing Techniques/instrumentation , Bacterial Typing Techniques/methods , Cell Line, Tumor , Cellulose/metabolism , Escherichia coli K12/chemistry , Feces/microbiology , Fimbriae Proteins/metabolism , Gastrointestinal Microbiome/drug effects , Humans , Mannans/metabolism , Paper , Protein BindingABSTRACT
The fabrication of a fully bio-sourced adsorbent of Cd(II) by covalent immobilization of quinine on cellulose paper is described. The double bond of commercially available quinine was converted to a terminal alkyne function which was reacted with cellulose paper, chemically modified with azide functions, through a 1,3-dipolar cycloaddition, leading to Cell-Quin. The adsorption efficiency of Cell-Quin was investigated to determine the optimal pH, contact time and dose of adsorbent, ultimately leading to high levels of removal. The mechanism of adsorption of Cell-Quin was deeply rationalized through kinetic experiments and isotherm modeling. We also showed that Cell-Quin could adsorb other heavy metals such as Cu(II), Pb(II), Ni(II) and Zn (II).
Subject(s)
Cadmium/isolation & purification , Quinine/chemistry , Water Pollutants, Chemical/isolation & purification , Adsorption , Cellulose , Hydrogen-Ion Concentration , Kinetics , Paper , ThermodynamicsABSTRACT
In the current study, we introduce photothiol-X chemistry as a powerful method to create hydrophobic patterns covalently grafted to the surface of cellulose paper. The general strategy builds on the use of a cellulose-based molecular printboard featuring disulfide functions which upon spatiocontrolled light irradiation at 365 nm allows robust photothiol-X ligations with hydrophobic moieties. A screening of structurally diverse molecular architectures as hydrophobic coating was conducted, and the most impressive result obtained with cholesterol moieties allows the creation of spatially well-resolved hydrophobic patterns with a contact angle of 140.8°. Our discoveries are supported by in-depth characterization studies using Fourier transform infrared spectroscopy, X-ray photoelectron spectrometry, and scanning electron microscopy analyses.