ABSTRACT
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.
ABSTRACT
A new approach exploiting the dual properties of thiol-grafted cellulose paper for promoting copper-catalyzed [3+2]-cycloadditions of organic azides with alkynes and adsorbing residual copper species in solution was developed. The thiol-grafted cellulose paper, used as a paper strip, effects the reduction of CuII to catalytically active CuI and acts as a powerful adsorbent for copper, thereby facilitating the work-up process and leaving the crude mixture almost free of copper residues after a single filtration.
ABSTRACT
A biomimetic device for the reduction of Cu(ii) to Cu(i) consisting of thioglycolic acid covalently grafted to cellulose paper was developed. The device displays exceptionally fast reducing properties allowing the reduction of Cu(ii) in seconds and the formation of deeply colored Cu(i)-SCH2R complexes onto the cellulose paper. This biomimetic and biomaterial-based concept was exploited for the detection of copper in water samples with a limit of detection as low as 2 ppm.
Subject(s)
Biomimetic Materials/chemistry , Copper/analysis , Biomimetics , Cellulose/chemistry , Colorimetry , Copper/chemistry , Hydrogen-Ion Concentration , Limit of Detection , Microscopy, Electron, Scanning , Oxidation-Reduction , Paper , Photoelectron Spectroscopy , Spectroscopy, Fourier Transform Infrared , Thioglycolates/chemistryABSTRACT
A portable, recyclable and highly selective paper-based sensor device for the colorimetric and optical detection of hydrogen sulfate anions in water was developed. The detection system features a rhodamine-based sensor covalently grafted onto the highly hydrophilic surface of cellulose paper.
