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.

In this work, we will present a novel approach for the detection of small molecules with molecularly imprinted polymer (MIP)-type receptors. This heat-transfer method (HTM) is based on the change in heat-transfer resistance imposed upon binding of target molecules to the MIP nanocavities. Simultaneously with that technique, the impedance is measured to validate the results. For proof-of-principle purposes, aluminum electrodes are functionalized with MIP particles, and L-nicotine measurements are performed in phosphate-buffered saline solutions. To determine if this could be extended to other templates, histamine and serotonin samples in buffer solutions are also studied. The developed sensor platform is proven to be specific for a variety of target molecules, which is in agreement with impedance spectroscopy reference tests. In addition, detection limits in the nanomolar range could be achieved, which is well within the physiologically relevant concentration regime. These limits are comparable to impedance spectroscopy, which is considered one of the state-of-the-art techniques for the analysis of small molecules with MIPs. As a first demonstration of the applicability in biological samples, measurements are performed on saliva samples spiked with L-nicotine. In summary, the combination of MIPs with HTM as a novel readout technique enables fast and low-cost measurements in buffer solutions with the possibility of extending to biological samples.

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.

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. † Electronic supplementary information (ESI) available: Details of the experimental setups, ESI-MS calibration information and complementary experimental data. See Scheme 2 Synthetic pathway towards sequence controlled SUMI-1A, SUMI-2AB and SUMI-3ABC using radical monomer insertion via RAFT polymerization. Polymer Chemistry PaperThis journal is

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.

The phase transitions of binary lipid mixtures are studied by a combination of Peltier-element-based adiabatic scanning calorimetry (pASC) and quartz crystal microbalance with dissipation monitoring (QCM-D). pASC, a novel type of calorimeter, provides valuable and unambiguous information on the heat capacity and the enthalpy, whereas QCM-D is proposed as a genuine way of determining phase diagrams by analysing the temperature dependence of the viscosity. Two binary mixtures of phospholipids with the same polar head and differing in the alkyl chain length, DMPC + DPPC and DMPC + DSPC, are discussed. Both techniques give consistent phase diagrams, which compare well with literature results, showing their capability to map the phase behaviour of pure lipids as well as lipid mixtures. This work can be considered as a departure point for further investigations on more complex lipid mixtures displaying relevant phases such as the liquid-ordered phase and solid-lipid interfaces with biologically functional importance.

An electrochemical route to poly( p-phenylenevinylenes) (PPVs) is described which involves cathodic cleavage of bis(dibromomethy1)arenes at a mercury pool cathode. Insoluble and organosolv PPVs are obtained in good yields and are characterised as regular and linear. Copolymers are obtained by co-electrolysis of different bis(dibromomethy1)arenes. The method is versatile and much functionality is tolerated. The polymers can be made conducting by doping with BF, or SO3. The effect of substituents on conductivity correlates, roughly but significantly, with Hammett o-values.Poly( p-phenylenevinylene), the parent PPV, forms conducting blends with poly(viny1 alcohol).-f This paper is Part 44 of a series entitled 'Electroorganic Reactions'.

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.