Sustainable Electropolymerization of Zingerone and Its C2 Symmetric Dimer for Amperometric Biosensor Films.

Polymeric permselective films are frequently used for amperometric biosensors to prevent electroactive interference present in the target matrix. Phenylenediamines are the most commonly used for the deposition of shielding polymeric films against interfering species; however, even phenolic monomers have been utilized in the creation of these films for microsensors and biosensors. The purpose of this paper is to evaluate the performances of electrosynthesized polymers, layered by means of constant potential amperometry (CPA), of naturally occurring compound zingerone (ZING) and its dimer dehydrozingerone (ZING DIM), which was obtained by straight oxidative coupling reaction. The polymers showed interesting shielding characteristics against the main interfering species, such as ascorbic acid (AA): actually, polyZING exhibited an AA shielding aptitude comprised between 77.6 and 99.6%, comparable to that obtained with PPD. Moreover, a marked capability of increased monitoring of hydrogen peroxide (HP), when data were compared with bare metal results, was observed. In particular, polyZING showed increases ranging between 55.6 and 85.6%. In the present work, the molecular structures of the obtained polymers have been theorized and docking analyses were performed to understand their peculiar characteristics better. The structures were docked using the Lamarckian genetic algorithm (LGA). Glutamate biosensors based on those polymers were built, and their performances were compared with biosensors based on PPD, which is the most widespread polymer for the construction of amperometric biosensors.

Antimicrobial activity of gaseous Citrus limon var pompia leaf essential oil against Listeria monocytogenes on ricotta salata cheese.

Contamination by Listeria monocytogenes is a particularly challenging problem in the food industry due to the ability of the bacterium to develop under conditions normally used for food preservation. Here, we show that the gaseous phase of Citrus limon var pompia leaf essential oil (hereafter PLEO) exerts specific anti-Listeria activity on ricotta salata cheese stored at 5 °C. The synergic effect of gaseous PLEO treatment and refrigeration was first confirmed in vitro on L. monocytogenes strains treated for 3 h with gaseous PLEO and then stored at 5 °C. Ricotta cheese was then inoculated with L. monocytogenes strains and subjected to hurdle technology with different concentrations of gaseous PLEO. Cell counts revealed gaseous PLEO to exert a bactericidal effect on L. monocytogenes 20600 DSMZ and a bacteriostatic effect on a mix of L. monocytogenes strains. Scanning and transmission electron microscopy analyses of L. monocytogenes cells suggested that gaseous PLEO targets the bacterial cell wall and plasma membrane. Chemical analyses of the liquid and vapor phases of PLEO indicated linalyl acetate to be the predominant compound, followed by limonene and the two isomers of citral, whereas EO composition analysis, although generally in line with previous findings, showed the presence of linalyl acetate for the first time. Solid-phase microextraction coupled with gas chromatography confirmed the presence of all crude oil components in the headspace of the box.

A Storage-Dependent Platinum Functionalization with a Commercial Pre-Polymer Useful for Hydrogen Peroxide and Ascorbic Acid Detection.

A preliminary assessment of properties of the commercial product Chemiplus 2DS HB (BI-QEM Specialties SpA) is proposed. Cyclic voltammetry of this oligomer containing sulfate/sulfone groups shows a single oxidative peak at +0.866 V vs. Ag/AgCl, and its passivating process on Pt electrode suggests the formation of a non-conductive layer. Electrode modification was achieved by exploiting the constant potential amperometry setting potential at +0.900 V vs. Ag/AgCl. A substantial change in the oxidative currents from electroactive species H2O2 and ascorbic acid (AA) were observed on Pt/Chemiplus 2DS HB sensors compared to unmodified Pt. Furthermore, the influence of different storage conditions on modified sensors was examined. A storage solution containing AA concentration from 0.1 until 10 mM maintained effective AA rejection of Pt/Chemiplus 2DS HB after 7 days from construction; H2O2 oxidation capability was also retained. Sulfone and sulfonate groups of Chemiplus 2DS HB are likely responsible for the dimensionality of the film and the electrostatic interaction leading to a self-blocking/self-rejection of AA. The way Pt/Chemiplus can reveal the AA presence depends on the maintaining of AA rejection, and this peculiarity can distinguish it from other sensors or biosensors.

Intrahepatic bile duct primary cilia in biliary atresia.

AIM: The etiopathogenesis of non-syndromic biliary atresia (BA) is obscure. The primary aim was to investigate intrahepatic bile duct cilia (IHBC) in BA at diagnosis and its correlation with clinical outcome. The secondary aim was to analyze IHBC in routine paraffin-embedded liver biopsies using conventional scanning electron microscopy (SEM). METHODS: Surgical liver biopsies taken at diagnosis from 22 BA infants (age range, 39-116 days) and from eight children with non-BA chronic cholestasis (age range, 162 days -16.8 years) were evaluated for IHBC by immunofluorescence (IF) and SEM. A minimum 18-month follow-up after surgery was available for all patients. RESULTS: By IF, cilia were present in 6/8 (75%) non-BA but only in 3/22 (14%) BA cases, and cilia were reduced or absent in 19/22 (86%) BA and 2/8 (25%) non-BA livers (P < 0.01). In BA, cilia presence was found to be associated with clearance of jaundice at 6-month follow-up (P < 0.05). However, high overall survival rates with native liver, >90% at 12 months, and >70% at 24 months post-surgery, were recorded regardless of cilia presence/absence at diagnosis. Electron microscopy was able to detect bile ducts and cilia in routine liver biopsies, revealing significant abnormalities in 100% BA livers. CONCLUSIONS: The presence of IHBC in BA livers at the diagnosis was associated with resolution of cholestasis, although was not predictive of short-term survival with native liver. Scanning electron microscopy represents a powerful new tool to study routine liver biopsies in biliary disorders. Cilia dysfunction in BA pathogenesis and/or disease progression warrants further investigation.

Electropolymerized phenol derivatives as permselective polymers for biosensor applications.

Amperometric biosensors are often coated with a polymeric permselective film to avoid electroactive interference by reducing agents present in the target medium. Phenylenediamine and phenol monomers are commonly used to form these permselective films in the design of microsensors and biosensors. This paper aims to evaluate the permselectivity, stability and lifetime of polymers electrosynthesized using either constant potential amperometry (CPA) or cyclic voltammetry (CV) from naturally occurring phenylpropanoids in monomeric and dimeric forms (eugenol, isoeugenol, dehydrodieugenol and magnolol). Sensors were characterized by scanning electron microscopy and permselectivity analysis. Magnolol formed an electro-deposited polymer with a more defined three-dimensional texture in comparison with the other films. The phenol-derived films showed different permselectivity towards H2O2 over ascorbic acid and dopamine, likely to be related to the thickness and compactness of the polymer. The CV-derived films had a better permselectivity compared to the CPA-corresponding polymers. Based on these results, the permselectivity, stability and lifetime of a biosensor for glucose were studied when a magnolol coating was electro-deposited. The structural principles governing the permselectivity of the magnolol-derived film are suggested to be mainly related to the conformational flexibility of this monomer. Newly designed biosensors, coated with electropolymerized natural phenol derivatives, may represent promising analytical devices for different application fields.

UV light and adaptive divergence of leaf physiology, anatomy, and ultrastructure drive heat stress tolerance in genetically distant grapevines.

The genetic basis of plant response to light and heat stresses had been unveiled, and different molecular mechanisms of leaf cell homeostasis to keep high physiological performances were recognized in grapevine varieties. However, the ability to develop heat stress tolerance strategies must be further elucidated since the morpho-anatomical and physiological traits involved may vary with genotype × environment combination, stress intensity, and duration. A 3-year experiment was conducted on potted plants of Sardinian red grapevine cultivars Cannonau (syn. Grenache) and Carignano (syn. Carignan), exposed to prolonged heat stress inside a UV-blocking greenhouse, either submitted to low daily UV-B doses of 4.63 kJ m-2 d-1 (+UV) or to 0 kJ m-2 d-1 (-UV), and compared to a control (C) exposed to solar radiation (4.05 kJ m-2 d-1 average UV-B dose). Irrigation was supplied to avoid water stress, and canopy light and thermal microclimate were monitored continuously. Heat stress exceeded one-third of the duration inside the greenhouse and 6% in C. In vivo spectroscopy, including leaf reflectance and fluorescence, allowed for characterizing different patterns of leaf traits and metabolites involved in oxidative stress protection. Cannonau showed lower stomatal conductance under C (200 mmol m-2 s-1) but more than twice the values inside the greenhouse (400 to 900 mmol m-2 s-1), where water use efficiency was reduced similarly in both varieties. Under severe heat stress and -UV, Cannonau showed a sharper decrease in primary photochemical activity and higher leaf pigment reflectance indexes and leaf mass area. UV-B increased the leaf pigments, especially in Carignano, and different leaf cell regulatory traits to prevent oxidative damage were observed in leaf cross-sections. Heat stress induced chloroplast swelling, plastoglobule diffusion, and the accumulation of secretion deposits in both varieties, aggravated in Cannonau -UV by cell vacuolation, membrane dilation, and diffused leaf blade spot swelling. Conversely, in Carignano UV-B, cell wall barriers and calcium oxalate crystals proliferated in mesophyll cells. These responses suggest an adaptive divergence among cultivars to prolonged heat stress and UV-B light. Further research on grapevine biodiversity, heat, and UV-B light interactions may give new insights on the extent of stress tolerance to improve viticulture adaptive strategies in climate change hotspots.

Nanosuspension-Based Dissolvable Microneedle Arrays to Enhance Diclofenac Skin Delivery.

Applying a formulation on the skin represents a patient-acceptable and therapeutically effective way to administer drugs locally and systemically. However, the stratum corneum stands as an impermeable barrier that only allows a very limited number of drugs to be distributed in the underlying tissues, limiting the feasibility of this administration route. Microneedle arrays are minimally invasive platforms that allow the delivery of drugs within/across the skin through the temporary mechanical disruption of the stratum corneum. In this work, microneedle arrays were combined with nanosuspensions, a technology for solubility enhancement of water insoluble molecules, for the skin delivery of diclofenac. Nanosuspensions were prepared using a top-down method and loaded in the tips of 500 µm or 800 µm high microneedles. The quality of the combined platform was assessed using electron microscopy and spectroscopic and calorimetry techniques, demonstrating the ability to load high amounts of the hydrophobic drug and the compatibility between excipients. Lastly, the application of nanosuspension-loaded microneedles on the skin in vitro allowed the delivery of diclofenac within and across the stratum corneum, proving the potential of this combination to enhance skin delivery of scarcely soluble drugs.

TEM morphological characterization of a one-step self-etching system applied clinically to human caries-affected dentin and deep sound dentin.

PURPOSE: To examine morphologically the hybrid layer of one-step self-etching adhesive, Clearfil S3 Bond (S3bond), in caries-affected dentin (CAD) and deep sound dentin (DSD) cavities performed clinically. For a comparative group, the two-step self etching adhesive Clearfil Protect Bond (Pbond) was used in a similar clinical situation. METHODS: This study was carried out on carious and sound teeth clinically selected for extraction. In carious teeth, CAD was obtained by way of subjective criteria by removing infected tissue to form a cavity bottom. DSD was obtained at a depth of 4 mm in the dentin cavity of sound teeth. S3bond and Pbond were applied in the CAD and DSD cavities as indicated by the manufacturer, followed by a composite restoration. Teeth were extracted about 20 minutes after the bonding procedure, and processed for TEM analysis. RESULTS: Expression of S3bond in CAD was morphologically highly variable. When affected tubules were occluded by intratubular mineralized deposits, the interface displayed a dense poly-HEMA hydrogel as water sorption by the hydrophilic S3bond toward the porous affected collagen. Conversely, when tubules appeared empty, voids of various sizes were formed by tubular fluid shift. In DSD, S3bond clearly exhibited voids and water channels as signs of the high permeability of the sub-surface. Although porosities were somewhat retained, Pbond expression showed a hermetic character which was independent of the dentin substrate.

First characterization of a Bronze Age textile fibre from Sardinia (Italy).

This paper describes a case study of a linen yarn found inside a spiral bronze necklace fragment during an excavation campaign in la Prisgiona, a Nuragic settlement, near Arzachena, in north-east Sardinia. The site is one of the most interesting settlements of the Nuragic period. Abandoned after a fire, it was no longer inhabited, thus allowing the preservation of the Nuragic stratigraphy. The necklace fragments are part of a votive burial and the yarn is the only known textile material belonging to the Bronze Age period from Sardinia. The uniqueness of the finding, in the rare corpus of prehistoric textile materials, and the small amount of it available do not allow conventional analyses and requires a non-invasive/micro-invasive method. The protocol established to preserve as much as possible the entirety of the object, involving polarize light microscopy, portable ATR-FTIR, SEM-EDS, micro X-ray Computer Tomography and XRD, was successfully used to extend knowledge about the materials and techniques of this civilisation.

Needle-Free Jet Injectors and Nanosuspensions: Exploring the Potential of an Unexpected Pair.

Needle-free liquid jet injectors are medical devices used to administer pharmaceutical solutions through the skin. Jet injectors generate a high-speed stream of liquid medication that can puncture the skin and deliver the drug to the underlying tissues. In this work, we investigated the feasibility of using liquid jet injectors to administer nanosuspensions, assessing the impact of the jet injection on their pharmaceutical and physicochemical properties. For this purpose, the model drug diclofenac was used to prepare a set of nanosuspensions, stabilized by poloxamer 188, and equilibrated at different pHs. The hydrodynamic diameter and morphology of the nanocrystals were analyzed before and after the jet injection across porcine skin in vitro, together with the solubility and release kinetics of diclofenac in a simulated subcutaneous environment. The efficacy of the jet injection (i.e., the amount of drug delivered across the skin) was evaluated for the nanosuspension and for a solution, which was used as a control. Finally, the nanosuspension was administered to rats by jet injector, and the plasma profile of diclofenac was evaluated and compared to the one obtained by jet injecting a solution with an equal concentration. The nanosuspension features were maintained after the jet injection in vitro, suggesting that no structural changes occur upon high-speed impact with the skin. Accordingly, in vivo studies demonstrated the feasibility of jet injecting a nanosuspension, reaching relevant plasma concentration of the drug. Overall, needle-free jet injectors proved to be a suitable alternative to conventional syringes for the administration of nanosuspensions.

Nanocrystals as an effective strategy to improve Pomalidomide bioavailability in rodent.

Pomalidomide (POM) is an FDA-approved immunomodulatory imide drug (IMiDs) an it is effectively used in the treatment of multiple myeloma. IMiDs are analogs of the drug thalidomide and they have been repurposed for the treatment of several diseases such as psoriatic arthritis and Kaposi Sarcoma. In recent years, IMiDs have been also evaluated as a new treatment for neurological disorders with an inflammatory and neuroinflammatory component. POM draws particular interest for its potent anti-TNF-α activity at significantly lower concentrations than the parent compound thalidomide. However, POM's low water solubility underpins its low gastrointestinal permeability resulting in irregular and poor absorption. The purpose of this work was to prepare a POM nanocrystal-based formulation that could efficiently improve POM's plasma and brain concentration after intraperitoneal injection. POM nanocrystals prepared as a nanosuspension by the media milling method showed a mean diameter of 219 nm and a polydispersity index of 0.21. POM's nanocrystal solubility value (22.97 µg/mL) in phosphate buffer was about 1.58 folds higher than the POM raw powder. Finally, in vivo studies conducted in adult Male Sprague-Dawley rats indicated that POM nanocrystal ensured higher and longer-lasting drug levels in plasma and brain when compared with POM coarse suspension.

Pulmonary Delivery of Curcumin and Beclomethasone Dipropionate in a Multicomponent Nanosuspension for the Treatment of Bronchial Asthma.

Curcumin has shown a potential extraordinary activity as an add-on ingredient in asthma treatment, due to its immunomodulatory and anti-inflammatory mechanism of action. However, its low water solubility and bioavailability lead to a poor therapeutic effect, which can be overcome by its formulation as nanocrystals. The aim of this study was to prepare a multicomponent formulation for the delivery of curcumin (CUR) and beclomethasone dipropionate (BDP) into the lungs as water-based nanosuspensions (NS). Single component formulations (CUR-NS, BDP-NS) and a multicomponent formulation (CUR+BDP-NS) were prepared through a wet ball media milling technique, using P188 as a non-toxic stabilizer. Characterization was carried out in terms of size, size distribution, zeta potential, nanocrystals morphology, and solid-state properties. Moreover, the inhalation delivery efficiency was studied with Next Generation Impactor (NGI, Apparatus E Ph. Eu). CUR-NS was optimized and showed a long-term stability and improved nanocrystals apparent solubility. The three formulations exhibited a nanocrystal mean diameter in the range of 200-240 nm and a homogenous particle size distribution. Aggregation or sedimentation phenomena were not observed in the multicomponent formulation on 90 days storage at room temperature. Finally, the nebulization tests of the three samples showed optimal aerodynamic parameters and MMAD < 5 µm.

Zoxamide accumulation and retention evaluation after nanosuspension technology application in tomato plant.

BACKGROUND: Low water solubility of pesticide requires formulations with high levels of stabilizers and organic solvents. Moreover, only 0.1% of the applied pesticides formulation reaches the target, while 99.9% spreads in the surrounding environment. Therefore, there is the need for more efficient and environmentally sustainable alternatives. RESULTS: Zoxamide (ZO) nanosuspension was prepared through a media milling technique by using the stabilizer polysorbate 80. The thin and acicular crystals obtained, showed particle size of 227 nm, polydispersion index of 0.247 and zeta potential of -28 mV. Dimensional data and morphology of ZO nanocrystals alone, on tomato leaves and berries, were confirmed by scanning electron microscopy. The reduction in size for ZO crystals obtained after the milling process increased pesticide water solubility till 39.6 mg L-1 , about 1.6 the solubility obtained with a conventional commercial formulation. Field and dip contamination trials performed on tomato plants showed the nanosuspension's ability to increase ZO deposition and accumulation versus a coarse ZO suspension and commercial formulation, respectively. CONCLUSIONS: The nanoformulation proposed, resulted in low cost and was easy to make. Moreover, the organic solvent-free composition together with a low surfactant addition assured a minor environmental impact. Finally, the increased retention and deposition of the fungicide can reduce the amounts of ZO formulation applied to tomatoes. © 2021 Society of Chemical Industry.

An Ascorbate Bluetooth© Analyzer for Quality Control of Fresh-Cut Parsley Supply Chain.

This work provides companies in the fresh-cut produce sector with an Ascorbate Bluetooth© Analyzer (ABA), a screen-printed sensor-based device for ascorbic acid (AA) detection, for quality control all along the supply chain. The amperometric detection of AA on fresh and fresh-cut parsley, under correct and incorrect storage temperature, allowed us to investigate the kinetics of AA decay in response to oxidative stress. The role of ascorbate oxidase (AOx) and ascorbate peroxidase (APx) was studied. ABA was used in situ by unskilled personnel. Treatments influenced AA decay kinetics, which were linear in fresh parsley, and non-linear in fresh-cut. Two hours at 28 °C immediately after chopping, the resilience of the fresh-cut parsley was reduced, even though the cold chain was restored. Two hours at -2 °C caused a rapid loss of AA until its complete decay after 72 h. Significant differences between treatments were observed in both the expression and activity of AOx and APx. ABA registered sudden changes of parsley AA following unpredicted variations of temperature during processing or transport. It was useful to remedy the effects of unexpected flaws in the cold chain, which can be proposed for quality preservation of different fresh-cut produce.

Nanosuspensions and Microneedles Roller as a Combined Approach to Enhance Diclofenac Topical Bioavailability.

Topical application of the anti-inflammatory drug diclofenac (DCF) reduces the severity of systemic unwanted effects compared to its oral administration. A number of transdermal formulations are available on the market and routinely used in clinical and home-care settings. However, the amount of DCF delivered across the skin remains limited and often insufficient, thus making the oral route still necessary for achieving sufficient drug concentration at the inflamed site. In attempting to improve the transdermal penetration, we explored the combined use of DCF nanosuspensions with a microneedle roller. Firstly, DCF nanosuspensions were prepared by a top-down media milling method and characterized by spectroscopic, thermal and electron microscopy analyses. Secondly, the pore-forming action of microneedle rollers on skin specimens (ex vivo) was described by imaging at different scales. Finally, DCF nanosuspensions were applied on newborn pig skin (in vitro) in combination with microneedles roller treatment, assessing the DCF penetration and distribution in the different skin layers. The relative contribution of microneedle length, nanosuspension stabilizer and application sequence could be identified by systemically varying these parameters.

FLO11 gene length and transcriptional level affect biofilm-forming ability of wild flor strains of Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, FLO11 encodes an adhesin that is associated with different phenotypes, such as adherence to solid surfaces, hydrophobicity, mat and air-liquid biofilm formation. In the present study, we analysed FLO11 allelic polymorphisms and FLO11-associated phenotypes of 20 flor strains. We identified 13 alleles of different lengths, varying from 3.0 to 6.1 kb, thus demonstrating that FLO11 is highly polymorphic. Two alleles of 3.1 and 5.0 kb were cloned into strain BY4742 to compare the FLO11-associated phenotypes in the same genetic background. We show that there is a significant correlation between biofilm-forming ability and FLO11 length both in different and in the same genetic backgrounds. Moreover, we propose a multiple regression model that allows prediction of air-liquid biofilm-forming ability on the basis of transcription levels and lengths of FLO11 alleles in a population of S. cerevisiae flor strains. Considering that transcriptional differences are only partially explained by the differences in the promoter sequences, our results are consistent with the hypothesis that FLO11 transcription levels are strongly influenced by genetic background and affect biofilm-forming ability.

The Presence of Polysaccharides, Glycerol, and Polyethyleneimine in Hydrogel Enhances the Performance of the Glucose Biosensor.

The use of amperometric biosensors has attracted particular attention in recent years, both from researchers and from companies, as they have proven to be low-cost, reliable, and very sensitive devices, with a wide range of uses in different matrices. The continuous development of amperometric biosensors, since their use involves an enzyme, is specifically aimed at keeping and increasing the catalytic properties of the loaded protein, so as to be able to use the same device over time. The present study aimed to investigate the impact of glycerol and polysaccharides, in the presence of polycationic substances to constitute a hydrogel, in enhancing the enzymatic and analytic performance of a glucose biosensor. Initially, it was possible to verify how the deposition of the starch-based hydrogel, in addition to allowing the electropolymerization of the poly(p-phenylenediamine) polymer and the maintenance of its ability to shield the ascorbic acid, did not substantially limit the permeability towards hydrogen peroxide. Moreover, different biosensor designs, loading a mixture containing all the components (alone or in combination) and the enzyme, were tested in order to evaluate the changes of the apparent enzyme kinetic parameters, such as VMAX and KM, and analytical response in terms of Linear Region Slope, highlighting how the presence of all components (starch, glycerol, and polyethyleneimine) were able to substantially enhance the performance of the biosensors. The surface analysis of the biosensors was performed by scanning electron microscope (SEM). More, it was shown that the same performances were kept unchanged for seven days, proving the suitability of this biosensor design for short- and mid-term use.

Ketoprofen spray-dried microspheres based on Eudragit RS and RL: study of the manufacturing parameters.

The preparation of ketoprofen spray-dried microspheres can be affected by the long drug recrystallization time. Polymer type and drug-polymer ratio as well as manufacturing parameters affect the preparation. The purpose of this work was to evaluate the possibility to obtain ketoprofen spray-dried microspheres using the Eudragit RS and RL; the influence of the spray-drying parameters on morphology, dimension, and physical stability of microspheres was studied. Ketoprofen microspheres based on Eudragit blend can be prepared by spray-drying and the nebulization parameters do not influence significantly particle properties; nevertheless, they can be affected by drying and storage methods. No effect of the container material is found.

Use of ß-cyclodextrin as enhancer of ascorbic acid rejection in permselective films for amperometric biosensor applications.

Interference rejection in amperometric biosensors can be more effective introducing some modifiers during electro-deposition of permselective film. Addition of ß-cyclodextrin (ßCD), a cyclic oligosaccharide composed of seven glucose units, to the ortho-phenylendiamine (oPD) monomer were already demonstrated to provide an enhancement in ascorbic acid (AA) rejection. Here we evaluated the improvement in permselectivity of poly-eugenol and poly-magnolol films electro-polymerized in presence of different amounts of ßCD or eugenol-ßCD inclusion complex for amperometric biosensor application. Starting from Pt-Ir wire as transducer several microsensors were covered with polymeric films doped with ßCD-based modifiers through constant potential amperometry. Characterization of modified polymers was achieved by scanning electron microscopy and permselectivity analysis. Poly-magnolol film in combination with ßCD showed a worsening in permselectivity compared to poly-magnolol alone. In contrast, the introduction of ßCD-based modifier enhanced the interference rejection toward the archetypal interferent AA, while slightly affecting permeability toward H2O2 compared to the poly-eugenol without modifier. The AA rejection seems to be influenced by the availability of ßCD cavity as well as film performance due to concentration of ßCD-Eugenol inclusion complex. A poly-eugenol film co-polymerized with 2 mM ßCD-eugenol inclusion complex showed a permselectivity equal to poly-orthophenylendiamine film (PPD), with a lower permeability to AA, likely to be related with a self-blocking mechanism. Based on these results, a biosensor for glutamate was constructed with a poly-eugenol doped with ßCD-eugenol as permselective layer and its permselectivity, stability and lifetime were determined.

Influence of lead in the sorption of arsenate by municipal solid waste composts: metal(loid) retention, desorption and phytotoxicity.

The ability of two municipal solid waste composts (MSW-C) to sorb As(V) in the presence of Pb(II) and in acidic conditions was investigated. Sorption isotherms and kinetics showed that both MSW-C were able to sorb As(V) in a similar way (∼0.24mmolg-1 MSW-C), but only when Pb(II) was present (0.45mmolL-1). The concomitant sorption of Pb(II) by both MSW-C (∼0.40mmolg-1) suggested that the metal cation was likely acting as bridging element between the negatively charged functional groups of composts and As(V). SEM-EDX analysis of the MSW-C+Pb(II)+As(V) systems supported the association between Pb(II) and As(V), while sequential extraction procedures and organic acids treatment showed that As(V) was strongly retained by MSW-C+Pb(II) and suggested the presence of different interaction types between As(V) and Pb(II). Plant growth experiments highlighted the key role of Pb(II) in the reduction of As(V)-phytotoxicity for triticale plants (×Triticosecale Wittm.) in the presence of MSW-C.