Selective PQQPFPQQ Gluten Epitope Chemical Sensor with a Molecularly Imprinted Polymer Recognition Unit and an Extended-Gate Field-Effect Transistor Transduction Unit.

A molecularly imprinted polymer (MIP) recognition system was devised for selective determination of an immunogenic gluten octamer epitope, PQQPFPQQ. For that, a thin MIP film was devised, guided by density functional theory calculations, and then synthesized to become the chemosensor recognition unit. Bis(bithiophene)-based cross-linking and functional monomers were used for this synthesis. An extended-gate field-effect transistor (EG-FET) was used as the transduction unit. The EG-FET gate surface was coated with the PQQPFPQQ-templated MIP film, by electropolymerization, to result in a complete chemosensor. X-ray photoelectron spectroscopy analysis confirmed the presence of the PQQPFPQQ epitope, and its removal from the MIP film. The chemosensor selectively discriminated between the octamer analyte and another peptide of the same number of amino acids but with two of them mismatched (PQQQFPPQ). The chemosensor was validated with respect to both the PQQPFPQQ analyte and a real gluten extract from semolina flour. It was capable to determine PQQPFPQQ in the concentration range of 0.5-45 ppm with the limit of detection (LOD) = 0.11 ppm. Moreover, it was capable of determining gluten in real samples in the concentration range of 4-25 ppm with LOD = 4 ppm, which is a value sufficient for discriminating between gluten-free and non-gluten-free food products. The gluten content in semolina flour determined with the chemosensor well correlated with that determined with a commercial ELISA gluten kit. The Langmuir, Freundlich, and Langmuir-Freundlich isotherms were fitted to the epitope sorption data. The sorption parameters determined from these isotherms indicated that the imprinted cavities were quite homogeneous and that the epitope analyte was chemisorbed in them

The thiophene-based inherently chiral monomer family grows: molecular design and electrochemical properties

Our group has recently presented electroactive thiophenebased polyconjugated films of unprecedented chirality manifestations and enantiorecognition ability,[1] based on the "inherent chirality" concept, implying that the whole electroactive backbone coincides with the stereogenic element, consisting in a tailored torsion induced by an atropisomeric bi-benzothiophene scaffold. Such films are easily prepared as enantiopure electrode surfaces by electrooligomerization of (R) and (S) enantiopure monomer 1. Now, concurrently with the exploration of the applicative potentialities of this "parent" molecular material, both racemic and enantiopure, we are widening the class of available monomers designed according the same strategy, but with different atropisomeric heteroaromatic scaffolds, different side chains, and/or with the addition of a further stereogenic element. The electrochemical properties of a selection of the new inherently chiral monomers now available will be presented in detail and rationalized as a function of their molecular structure, also in the perspective of potential applications. With the contribution of Fondazione Cariplo, grant no. 2011-0417. [1] F. Sannicol\uf2, S. Arnaboldi, T. Benincori, V. Bonometti, R. Cirilli, L. Dunsch, W. Kutner, G. Longhi, P.R. Mussini, M. Panigati, M. Pierini, S. Rizzo, Angew. Chemie 2014, 53, 2623-2627

Biological regeneration of liquid sorbents after industrial purification of outlet gases

Biological regeneration of water and organic sorbents used in the absorption of hydrophilic and hydrophobic pollutants, respectively, was studied. In both cases biodegradation takes place in a membrane bioreactor. In the case of organic sorbents regeneration of the biodegradation process is integrated with the extraction of a given pollutant to water phase. In experiments carried out in this work, the proposed systems were tested using a strain of Pseudomonas fluorescens. For hydrophilic compounds experiments were performed using alcohols (1-butanol and 2-propanol) as model substrates. Applying the mathematical model of a membrane bioreactor elaborated previously, the values of pollutant concentration were determined and positively verified in the experiments. This system of water sorbent regeneration is fully satisfying. The process of biodegradation integrated with extraction was analysed on the basis of model compounds such as benzene and toluene. The study confirmed a possibility of organic sorbent (silicone oil) regeneration. However, due to a very high partition coefficient of benzene or toluene between the organic and aqueous phases, the process could be considered only for the case of their high concentrations in the gas directed to absorption

Two-step treatment of harmful industrial wastewater: an analysis of microbial reactor with integrated membrane retention for benzene and toluene removal

Standards for highly toxic and carcinogenic pollutants impose strict guidelines, requiring values close to zero, regarding the degradation of such pollutants in industrial streams. In many cases, classic bioremoval processes fail. Therefore, we proposed a stream leaving the microbial membrane bioreactor (MBR) that is directed to an additional membrane separation mode (NF/RO). Under certain conditions, the integrated process not only benefits the environment but may also increase the profitability of the bioreactor operation. An appropriate model was developed and tested in which the bioremoval of benzene and toluene by Pseudomonas fluorescens was used as an example. This paper presents equations for selecting the operation parameters of the integrated system to achieve the expected degree of industrial wastewater purification

Integrated process of VOCs microbial degradation

W pracy podjęto badania mające na celu wykorzystanie szczepów bakteryjnych do regeneracji sorbentów stosowanych do usuwania lotnych związków organicznych ze strumienia gazu. Dla wybranych związków: benzenu i butanolu-1 opracowano równania kinetyczne, równowagę procesu adsorpcji i absorpcji oraz desorpcji i ekstrakcji a następnie przeprowadzono proces zintegrowany: desorpcji z węgla aktywnego lub ekstrakcji z absorbera organicznego i biodegradacji.Studies devoted to microbial regeneration of sorbents used to remove volatile organic compounds from gas stream are presented in the paper. For selected compounds: benzene and butanol-1 kinetic equations and equilibrium of adsorption, absorption from gas, desorption and extraction to water phase were developed. Then the integrated process: desorption from activated carbon or extraction from organic absorbent and biodegradation process was carried out

Multifunctional reactors - turning-point or curiosity in chemical reaction engineering?

W pracy przeanalizowano typowe przypadki reaktora wielofunkcyjnego. Wskazano na korzyści i trudności wynikające z zastosowania takiego rozwiązania procesowego, zaproponowano kryterium oceny i wyznaczono przypadki o największym potencjale aplikacyjnym.In the study, typical cases of multifunctional reactor were analyzed. Advantages and difficulties that eventuate from the process application and evaluation criteria with the most application potential cases were indicated

Biological Regeneration of Liquid Sorbents after Industrial Purification of Outlet Gases

Biological regeneration of water and organic sorbents used in the absorption of hydrophilic and hydrophobic pollutants, respectively, was studied. In both cases biodegradation takes place in a membrane bioreactor. In the case of organic sorbents regeneration of the biodegradation process is integrated with the extraction of a given pollutant to water phase. In experiments carried out in this work, the proposed systems were tested using a strain of Pseudomonas fluorescens. For hydrophilic compounds experiments were performed using alcohols (1-butanol and 2-propanol) as model substrates. Applying the mathematical model of a membrane bioreactor elaborated previously, the values of pollutant concentration were determined and positively verified in the experiments. This system of water sorbent regeneration is fully satisfying. The process of biodegradation integrated with extraction was analysed on the basis of model compounds such as benzene and toluene. The study confirmed a possibility of organic sorbent (silicone oil) regeneration. However, due to a very high partition coefficient of benzene or toluene between the organic and aqueous phases, the process could be considered only for the case of their high concentrations in the gas directed to absorption

Efficiency of membrane bioreactor for processes with inhibition

W pracy zaprezentowano wyniki analizy modelu bioreaktora membranowego w odniesieniu do jego zdolności produkcyjnej. Porównano wpływ separacji membranowej na uzyskiwane wartości produktywności dla trzech rodzajów kinetyk mikrobiologicznych - prostej (Mono-da), z inhibicjąsubstratem oraz produktem. We wszystkich badanych przypadkach stwierdzono znaczny wzrost efektywności w porównaniu z chemostatem.An analysis of the membrane bioreactor model with respect to its productivity was presented in the paper. An influence of the membrane separation on the obtained productivity values for: Monod, substrate and product inhibition kinetics was discussed. In all cases a significant increase in the efficiency in comparison with chemostat was observed

Biological treatment of diluted industrial wastewater enhanced by membrane techniques

Do rozwiązania problemu doprowadzenia ścieków zawierających BTEX do wymaganego normami poziomu, zaproponowano powiązanie strefy biodegradacji z dwoma modułami membranowymi. Poprzez kilkukrotne zagęszczenie biomasy Acinetobacter baumannii przy kilkudniowych czasach przebywania udało się znacząco zmniejszyć stężenie benzenu w strumieniu opuszczającym układ biodegradacji. Aby jednak uzyskać stężenie spełniające normy, niezbędne jest doczyszczenie tego strumienia stosując RO lub NF.To solve a problem of purification of wastewater containing BTEX to the required standards, the integration of biodegradation zone and two membrane modules was proposed. The concentration of benzene in stream leaving the biodegradation zone was significantly reduced using the method of thickening Acinetobacter baumannii biomass several times in a few days residence time period. However, for concentrations meeting standards, it is necessary to purify deeper this stream using RO or NF

Usage of encapsulated enzymes in solution purification on the example of H>sub>2O2 removal

W pracy przedstawiono możliwości aplikacyjne preparatu z enkapsulowanym enzymem. Proces z jego zastosowaniem rozpatrzono na przykładzie katalazy, enzymu wykorzystywanego w przemyśle chemicznym i spożywczym do usuwania nadtlenku wodoru. Opracowano model procesu z udziałem enzymu enkapsulowanego w strukturze kulistej. Kluczowym parametrem modelu jest wartość modułu Thielego, którą ustala się poprzez dobór stężenia enzymu wewnątrz preparatu oraz rozmiar kapsułki. Obszar kinetyczny gwarantujący najpełniejsze wykorzystanie katalizatora występuje przy Ф < 0,3Application of encapsulated enzyme preparation is presented in the paper. The preparation was examined on the example of catalase - enzyme used in food and chemical industries to remove hydrogen peroxide. The process model in which the enzyme is encapsulated in a spherical structure was developed. A key parameter of this model is the Thiele modulus. Its value is controlled by the choice of enzyme concentration inside the preparation and a capsule size. A kinetic regime in which the catalyst is fully used was found for Φ < 0.