Polymers that carry donor-acceptor Stenhouse adducts (DASAs) are a very relevant class of light-responsive materials. Capable of undergoing reversible, photoinduced isomerisations under irradiation with visible light, DASAs allow for on-demand property changes to be performed in a non-invasive fashion. Applications include photothermal actuation, wavelength-selective biocatalysis, molecular capture and lithography.
View Article and Find Full Text PDFMixed-mode ion-exchange sorbents were introduced to improve the selectivity and retention of solid-phase extraction (SPE) sorbents. Mixed-mode ion-exchange sorbents integrate reversed-phase chemistry with ion-exchange groups to promote favourable interactions with ionic species. Nevertheless, a need to extract analytes with acidic and basic properties simultaneously within the same SPE cartridge led to the introduction of novel amphoteric/zwitterionic sorbents, which incorporate cation- and anion-exchange moieties within the same functional group attached to the polymeric network.
View Article and Find Full Text PDFIn the present work, a pair of molecularly imprinted polymers (MIPs) targeting distinct peptide targets were packed into trap columns and combined for automated duplex analysis of two low abundant small cell lung cancer biomarkers (neuron-specific enolase [NSE] and progastrin-releasing peptide [ProGRP]). Optimization of the on-line molecularly imprinted solid-phase extraction (MISPE) protocol ensured that the MIPs had the necessary affinity and selectivity towards their respective signature peptide targets - NLLGLIEAK (ProGRP) and ELPLYR (NSE) - in serum. Two duplex formats were evaluated: a physical mixture of the two MIPs (1:1 w/w ratio) inside a single trap column, and two separate MIP trap columns connected in series.
View Article and Find Full Text PDFThe identification and quantification of biomarkers is essential for the diagnosis, treatment, and long-term monitoring of many human diseases. In the present work, macromolecular synthetic receptors with pre-determined affinity and selectivity for the signature peptide of a prognostically significant small cell lung cancer (SCLC) biomarker - neuron-specific enolase (NSE) - were prepared in a porous polymer microsphere format using a template-directed synthesis strategy performed under precipitation polymerization conditions. The polymer microspheres were packed into short trap columns and then exploited as molecularly selective sorbents in a fully automated, on-line molecularly imprinted solid-phase extraction (MISPE) protocol.
View Article and Find Full Text PDFSolid-phase extraction (SPE) is a widely-used and very well-established sample preparation technique for liquid samples. An area of on-going focus for innovation in this field concerns the development of new and improved SPE sorbents that can enhance the sensitivity and/or the selectivity of SPE processes. In this context, mixed-mode ion-exchange sorbents have been developed and commercialised, thereby allowing enhanced capacity and selectivity to be offered by one single material.
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