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Powdered activated carbon (PAC) is an economical sorbent for removing micropollutants from water, but it generates hazardous dust that is flammable and a respiration hazard. Additionally, the fine particles of PAC can cake and block filters and membranes, complicating its use in continuous processes. In this study, we present a sulfur polymer support for PAC that overcomes these problems. The blend of the sulfur polymer and PAC generates low dust and it does not block filters. The utility of the sorbent is demonstrated in the remediation of water contaminated with perflurooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—persistent micropollutants that currently threaten water safety worldwide. Fundamental discoveries of PFOA self-assembly are also reported, as well as testing on a field sample of contaminated surface water. Refereed/Peer-reviewed

The Australian plant Acacia ligulata has a number of traditional food and medicinal uses by Australian Aboriginal people, although no bioactive compounds have previously been isolated from this species. Bioassay-guided fractionation of an ethanolic extract of the mature pods of A. ligulata led to the isolation of the two new echinocystic acid triterpenoid saponins, ligulatasides A (1) and B (2), which differ in the fine structure of their glycan substituents. Their structures were elucidated on the basis of 1D and 2D NMR, GC-MS, LC-MS/MS, and saccharide linkage analysis. These are the first isolated compounds from A. ligulata and the first fully elucidated structures of triterpenoid saponins from Acacia sensu stricto having echinocystic acid reported as the aglycone. Compounds 1 and 2 were evaluated for cytotoxic activity against a human melanoma cancer cell line (SK-MEL28) and a diploid fibroblast cell line (HFF), but showed only weak activity. Refereed/Peer-reviewed

Surface density gradients of streptavidin (SAV) were created on solid surfaces and demonstrated functionality as a bioconjugation platform. The surface density of immobilized streptavidin steadily increased in one dimension from 0 to 235 ng cm−2 over a distance of 10 mm. The density of coupled protein was controlled by its immobilization onto a polymer surface bearing a gradient of aldehyde group density, onto which SAV was covalently linked using spontaneous imine bond formation between surface aldehyde functional groups and primary amine groups on the protein. As a control, human serum albumin was immobilized in the same manner. The gradient density of aldehyde groups was created using a method of simultaneous plasma copolymerization of ethanol and propionaldehyde. Control over the surface density of aldehyde groups was achieved by manipulating the flow rates of these vapors while moving a mask across substrates during plasma discharge. Immobilized SAV was able to bind biotinylated probes, indicating that the protein retained its functionality after being immobilized. This plasma polymerization technique conveniently allows virtually any substrate to be equipped with tunable protein gradients and provides a widely applicable method for bioconjugation to study effects arising from controllable surface densities of proteins. Refereed/Peer-reviewed