As consumption of fish and fish-based foods increases, non-destructive monitoring of fish freshness also becomes more prominent. Fish products are very perishable and prone to microbiological growth, not always easily detected by organoleptic evaluation. The analysis of the headspace of fish specimens through gas sensing is an interesting approach to monitor fish freshness. Here we report a gas sensing method for monitoring Tilapia fish spoilage based on the application of a single gas sensitive gel material coupled to an optical electronic nose. The optical signals of the sensor and the extent of bacterial growth were followed over time, and results indicated good correlation between the two determinations, which suggests the potential application of this simple and low cost system for Tilapia fish freshness monitoring.

Photo-induced copper-mediated polymerization (photoCMP) is employed for the synthesis of multiarm-multiblock star copolymers. Based on a core-first approach, star polymers with four, six and twenty-one arms have been synthesized. Due to the high efficiency of the photoCMP process with respect to the reaction rate and end group functionality, each arm could be chain extended multiple times, allowing for up to 8 sequential polymerizations on the four-arm star and up to 4 blocks on the 21-arm star. Relatively high dilutions of the reaction mixtures and premature stopping of the polymerizations between 50–70% monomer conversion must be maintained in order to avoid the occurrence of star–star coupling reactions. For the optimization of the reactions, microreactor polymerizations were used to achieve economic and fast screening of the reactions. Flow reactors show improved control over the polymerizations, and also are beneficial in order to handle large amounts of solvents, which are required to synthesize the multiblock star polymers in significant quantities. By switching between an n-alkyl acrylate and tert-butyl acrylate (that can be hydrolyzed to acrylic acid segments after polymerization) in the chain extensions, hierarchically structured star polymers are obtained in which hydrophilic and hydrophobic blocks are alternated. These materials show pH responsiveness and complex self-assembly in the aqueous phase depending on the number of arms and the length of the individual blocks.

The reaction efficiency of single unit monomer insertion (SUMI) reactions via the reversible addition fragmentation chain transfer (RAFT) method is investigated in detail by the determination of obtained product yields of optimized batch and microflow synthesis procedures in combination with kinetic simulations of the radical insertion process. A method is developed to obtain exact concentration information on different SUMI products from calibration of the corresponding electrospray ionization mass spectra that are recorded on-line during synthesis. Experimental data show that isolated yields decrease for each subsequent SUMI reaction. This effect is investigated via kinetic modelling to understand which parameters have a beneficial or negative influence on the reaction outcome. Although most reaction conditions (such as monomer concentration or radical flux) do not play a considerable role in the obtainable yield of the insertion reaction, the model clearly shows that the propagation rate coefficient must display a strong chain-length dependency in order to explain the experimental observations. When taken into account, the simulations very well fit the experimental data obtained from optimized microreactor flow synthesis and recommendations for SUMI reactions are formulated. Finally, the optimized SUMI conditions obtained from microreactor experiments and kinetic modelling insights have been applied to upscale the SUMI synthesis reactions in a mesoflow reactor. This demonstrates the simple upscalability of continuous flow reactions and opens the pathway towards future synthesis of longer sequence controlled oligomers.

The cooperative assembly of biopolymers and small molecules can yield functional materials with precisely tunable properties. Here, the fabrication, characterization, and use of multicomponent hybrid gels as selective gas sensors are reported. The gels are composed of liquid crystal droplets self‐assembled in the presence of ionic liquids, which further coassemble with biopolymers to form stable matrices. Each individual component can be varied and acts cooperatively to tune gels' structure and function. The unique molecular environment in hybrid gels is explored for supramolecular recognition of volatile compounds. Gels with distinct compositions are used as optical and electrical gas sensors, yielding a combinatorial response conceptually mimicking olfactory biological systems, and tested to distinguish volatile organic compounds and to quantify ethanol in automotive fuel. The gel response is rapid, reversible, and reproducible. These robust, versatile, modular, pliant electro‐optical soft materials possess new possibilities in sensing triggered by chemical and physical stimuli.

Molecularly Imprinted Polymers (MIPs) were synthesised for the selective detection of amoxicillin in aqueous samples. Different functional monomers were tested to determine the optimal composition via batch rebinding experiments. Two different sensor platforms were tested using the same MIP solution; one being bulk synthesized and surface modified Screen Printed Electrodes (SPEs) via drop casting the microparticles onto the electrode surface and the other being UV polymerized directly onto the SPE surface in the form of a thin film. The sensors were used to measure amoxicillin in conjunction with the Heat-Transfer Method (HTM), a low-cost and simple thermal detection method that is based on differences in the thermal resistance at the solid–liquid interface. It was demonstrated that both sensor platforms could detect amoxicillin in the relevant concentration range with Limits of Detection (LOD) of 1.89 ± 1.03 nM and 0.54 ± 0.10 nM for the drop cast and direct polymerisation methods respectively. The sensor platform utilising direct UV polymerisation exhibited an enhanced response for amoxicillin detection, a reduced sensor preparation time and the selectivity of the platform was proven through the addition of nafcillin, a pharmacophore of similar shape and size. The use of MIP-modified SPEs combined with thermal detection provides sensors that can be used for fast and low-cost detection of analytes on-site, which holds great potential for contaminants in environmental aqueous samples. The platform and synthesis methods are generic and by adapting the MIP layer it is possible to expand this sensor platform to a variety of relevant targets.