Analytical Platforms at Swiss Universities of Applied Sciences.

Numerous projects and industrial and academic collaborations benefit from state-of-the-art facilities and expertise in analytical chemistry available at the Swiss Universities of Applied Sciences. This review summarizes areas of expertise in analytical sciences at the University of Applied Sciences and Arts Northwestern Switzerland (FHNW), the University of Applied Sciences and Arts Western Switzerland (HES-SO), and the Zurich University of Applied Sciences (ZHAW). We briefly discuss selected projects in different fields of analytical sciences.

Low-cost Portable Raman Instrument, a Tool toward Counterfeit Medication Identification.

We have successfully built a low-cost (under 500 CHF) portable Raman spectrometer based on scavenged, consumer electronics. The instrument prototype is designed as a tool to help identify counterfeit medication in low-income countries. As a proof of concept, we confirmed the presence of acetaminophen, a type of analgesic, in over-the-counter drugs from around the world.

On-line Monitoring and Control of Fed-batch Fermentations in Winemaking.

The fermentation of yeast in fed-batch mode shows great potential in winemaking because it allows the concentration of sugars to be kept low and constant throughout the process which, in turn, reduces cell stress and leads to a significant decrease in the production of unwanted secondary metabolites. The implementation of this technique requires reliable on-line analysis of sugar and a robust control strategy to maintain sugar concentrations at defined levels over the course of the fermentation. In this study, a laboratory-scale setup was used to implement and assess a fully automated fed-batch fermentation of Saccharomyces cerevisiae in grape must. Total sugar levels were monitored in-line by FT-MIR ATR spectroscopy and kept constant at 50 g/kg by a modified PI controller regulating the must feed flow rate. Good setpoint tracking and disturbance rejection were achieved in fermentations of up to four days despite occasional yeast sedimentation on the ATR crystal. The controller parameter adaptation strategy needs to be optimized for longer fermentations.

LDL-mimetic lipid nanoparticles prepared by surface KAT ligation for in vivo MRI of atherosclerosis.

Low-density lipoprotein (LDL)-mimetic lipid nanoparticles (LNPs), decorated with MRI contrast agents and fluorescent dyes, were prepared by the covalent attachment of apolipoprotein-mimetic peptide (P), Gd(iii)-chelate (Gd), and sulforhodamine B (R) moieties on the LNP surface. The functionalized LNPs were prepared using the amide-forming potassium acyltrifluoroborate (KAT) ligation reaction. The KAT groups on the surface of LNPs were allowed to react with the corresponding hydroxylamine (HA) derivatives of P and Gd to provide bi-functionalized LNPs (PGd-LNP). The reaction proceeded with excellent yields, as observed by ICP-MS (for B and Gd amounts) and MALDI-TOF-MS data, and did not alter the morphology of the LNPs (mean diameter: ca. 50 nm), as shown by DLS and cryoTEM analyses. With the help of the efficient KAT ligation, a high payload of Gd(iii)-chelate on the PGd-LNP surface (ca. 2800 Gd atoms per LNP) was successfully achieved and provided a high r 1 relaxivity (r 1 = 22.0 s-1 mM-1 at 1.4 T/60 MHz and 25 °C; r 1 = 8.2 s-1 mM-1 at 9.4 T/400 MHz and 37 °C). This bi-functionalized PGd-LNP was administered to three atherosclerotic apoE -/- mice to reveal the clear enhancement of atherosclerotic plaques in the brachiocephalic artery (BA) by MRI, in good agreement with the high accumulation of Gd in the aortic arch as shown by ICP-MS. The parallel in vivo MRI and ex vivo studies of whole mouse cryo-imaging were performed using triply functionalized LNPs with P, Gd, and R (PGdR-LNP). The clear presence of atherosclerotic plaques in BA was observed by ex vivo bright field cryo-imaging, and they were also observed by high emission fluorescent imaging. These directly corresponded to the enhanced tissue in the in vivo MRI of the identical mouse.

Toxicity assessment of pollutants sorbed on environmental sample microplastics collected on beaches: Part I-adverse effects on fish cell line.

Microplastics (MPs), are tiny plastic fragments from 1 µm to 5 mm generally found in the aquatic environment which can be easily ingested by organisms and may cause chronic physical but also toxicological effects. Toxicological assays on fish cell lines are commonly used as an alternative tool to provide fast and reliable assessment of the toxic and ecotoxic properties of chemicals or mixtures. Rainbow trout liver cell line (RTLW-1) was used to evaluate the toxicity of pollutants sorbed to MPs sampled in sandy beaches from different islands around the world during the first Race for Water Odyssey in 2015. The collected MPs were analyzed for polymer composition and associated persistent organic pollutants: polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT). In addition, DMSO-extracts from virgin MPs, MPs artificially coated with B[a]P and environmental MPs were analyzed with different bioassays: MTT reduction assay (MTT), ethoxyresorufin-O-deethylase (EROD) assay and comet assay. Microplastics from sand beaches were dominated by polyethylene, followed by polypropylene fragments with variable proportions. Organic pollutants found on plastic from beach sampling was PAHs (2-71 ng g-1). Samples from Bermuda (Somerset Long Bay) and Hawaii (Makapu'u) showed the highest concentration of PAHs and DDT respectively. No toxicity was observed for virgin microplastics. No cytotoxicity was observed on cells exposed to MP extract. However, EROD activity was induced and differently modulated depending on the MPs locations suggesting presence of different pollutants or additives in extract. DNA damage was observed after exposure to four microplastics samples on the six tested. Modification of EROD activity level and DNA damage rate highlight MPs extract toxicity on fish cell line.

Regioselective Synthesis of trans-1 Fullerene Bis-Adducts Directed by a Crown Ether Tether: Alkali Metal Cation Modulated Redox Properties of Fullerene-Crown Ether Conjugates.

Regioselective Bingel macrocyclization of C60 with a bis-malonate containing a novel dibenzo[18] crown-6 tether provides a versatile access to trans-1 fullerene bis-adducts such as (±)-1. Complexation of a potassium ion by (±)-1 has a pronounced effect on the redox properties of the carbon sphere as a result of the close proximity of the fullerene surface to the crown ether bound cation, which is enforced by the double bridging.

A cationic guest in a 24+ cationic host.

A new tetrahedral coordination cage M12L6 was prepared from a linear dipyrimidine ligand (L) and cis-protected palladium(II) (M). This cage showed unprecedented host-guest chemistry where the cationic host accommodated a cationic guest despite 24+ charges on the host framework. The unusual cation-cation host-guest chemistry is described by a unique onionlike shell structure of the host-guest complex where two cationic spheres are mediated by an anionic sphere of a counteranion assembly.