Immobilization of controlled Pu:Am ratio on actinide-specific affinity monolith support developed in capillary and coupled to inductively coupled plasma mass spectrometry.

The objective of this work was to develop an actinide-specific monolithic support in capillary designed to immobilize precise Pu:Am ratios and its coupling to inductively coupled plasma mass spectrometry (ICP-MS) for immobilized metal affinity chromatography applications. This format offers many advantages, such as reducing the sample amount and waste production, which are of prime importance when dealing with highly active radioelements. Four organic phosphorylated-based monoliths were synthesized in situ through UV photo-polymerization in capillary and characterized. The capillary coupling to ICP-MS was set up in conventional laboratory using Th and Sm as chemical analogues of Pu and Am. A dedicated method was developed to quantify online Th and Sm amounts immobilized on the monolithic capillaries, allowing to select the best monolith candidate poly(BMEP-co-EDMA)adp. By precisely adjusting the elemental composition in the loading solutions and applying the developed quantification method, the controlled immobilization of several Th:Sm molar ratios onto the monolith was successful. Finally, the capillary ICP-MS coupling was transposed in a glove box and by applying the strategy developed to design the monolithic support using Th and Sm, the immobilization of a 10.5 ± 0.2 (RSD = 2.3%, n = 3) Pu:Am molar ratio reflecting Pu ageing over 48 years was achieved in a controlled manner on poly(BMEP-co-EDMA)adp. Hence, the new affinity capillary monolithic support was validated, with only hundred nanograms or less of engaged radioelements and can be further exploited to precisely determine differential interactions of Pu and Am with targeted biomolecules in order to better anticipate the effect of Am on Pu biodistribution.

Metallic Nanoparticles Adsorbed at the Pore Surface of Polymers with Various Porous Morphologies: Toward Hybrid Materials Meant for Heterogeneous Supported Catalysis.

Hybrid materials consisting of metallic nanoparticles (NPs) adsorbed on porous polymeric supports have been the subject of intense research for many years. Such materials indeed gain from intrinsic properties, e.g., high specific surface area, catalytic properties, porous features, etc., of both components. Rational design of such materials is fundamental regarding the functionalization of the support surface and thus the interactions required for the metallic NPs to be strongly immobilized at the pore surface. Herein are presented some significant scientific contributions to this rapidly expanding research field. This contribution will notably focus on various examples of such hybrid systems prepared from porous polymers, whatever the morphology and size of the pores. Such porous polymeric supports can display pores with sizes ranging from a few nanometers to hundreds of microns while pore morphologies, such as spherical, tubular, etc., and/or open or closed, can be obtained. These systems have allowed some catalytic molecular reactions to be successfully undertaken, such as the reduction of nitroaromatic compounds or dyes, e.g., methylene blue and Eosin Y, boronic acid-based C-C homocoupling reactions, but also cascade reactions consisting of two catalytic reactions achieved in a row.

Contribution of the "Click Chemistry" Toolbox for the Design, Synthesis, and Resulting Applications of Innovative and Efficient Separative Supports: Time for Assessment.

The last two decades have seen the rapid expansion of click chemistry methodology in various domains closely related to organic chemistry. It has notably been widely developed in the area of surface chemistry, mainly because of the high-yielding character of reactions of the "click" type. Especially, this powerful chemical reaction toolbox has been adapted to the preparation of stationary phases from the corresponding chromatographic supports. A plethora of selectors can thus be immobilized on either organic, inorganic, or hybrid stationary phases that can be used in different chromatographic modes. This review first highlights the few different chemical ligation strategies of the "click" type that are up to now mainly devoted to the development of functionalized supports for separation sciences. Then, it gives in a second part an up-to-date survey of the different studies dedicated to the preparation of click chemistry-based chromatographic supports while highlighting the powerful and versatile character of the "click" ligation strategy for the design, synthesis, and developments of more and more complex systems that can find promising applications in the area of analytical sciences, in domains as varied as enantioselective separation, glycomics, proteomics, genomics, metabolomics, etc.

Uptake, accumulation and associated cellular alterations of environmental samples of microplastics in the seaworm Hediste diversicolor.

The ubiquitous distribution of microplastics (MPs) in the marine environment raises global concern to understand their impact. Environmental MPs have been shown to exhibit different physicochemical properties during their life cycles. However, the body of knowledge regarding their accumulation and biological effects is still significantly limited compared to manufactured MPs. To evaluate the hazardous effects of a mixture of environmental MPs collected along the Tunisian beaches, their accumulation and cellular effects were investigated in Hediste diversicolor. MP sample was composed of polyethylene (PE), polyethylene vinyl acetate (PEVA), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and polyamide (PA) analyzed using Raman microspectroscopy (RM). The concentrations of MPs in seaworm tissues increased over time, following the order 1.2-0.45 µm > 3-1.2 µm > 100-3 µm. The ingestion of MPs by H. diversicolor reduced their survival and growth, affected the neuro-transmission and antioxidant pathways. Our data emphasised that the toxic effects of environmental MPs were closely related to the exposure dose and period. The results also demonstrated that the size distribution of MPs in seaworms was mainly correlated with biochemical markers. This study highlights the ecological risk in the ingestion and accumulation of environmental MPs by biota that threatens their functional parameters.

A lab-on-a-chip for monolith-based preconcentration and electrophoresis separation of phosphopeptides.

A microdevice combining online preconcentration and separation of phosphopeptides was developed in a glass microchip. An ethylene glycol methacrylate phosphate (EGMP), acrylamide (AM) and bisacrylamide (BAA) based monolith was synthesized within microchannels through a photo-driven process. Morphological investigations revealed a homogeneous monolithic structure composed of uniform nodules (∼0.8 µm), with a large pore volume (0.62 cm3 g-1) and sufficiently high specific surface area (34.1 m2 g-1). These features make the monolith particularly interesting for preconcentration purposes. Immobilization of Zr4+ ions on the phosphate groups present at the poly(EGMP-co-AM-co-BAA) monolith surface leads to immobilized metal affinity chromatography support. This monolith-Zr4+ showed a great capacity to capture phosphopeptides. Successful preconcentration and separation of a mixture of ERK2 derived peptides differing only by their phosphorylation degree and sites could be achieved with signal enhancement factors between 340 and 910 after only 7 min of preconcentration. This integrated microdevice represents a novel approach for phosphoproteomic applications.

Microscope-assisted UV-initiated preparation of well-defined porous polymer monolithic plugs in glass microchips for peptide preconcentration.

Herein, highly defined monolithic beds were prepared in glass microchips by photopolymerization of ethylene glycol methacrylate phosphate (EGMP), acrylamide, and N,N'-methylenebisacrylamide (BAA) using an epifluorescence microscope as UV-irradiation source. Such a fast and easy method allowed precise control of (i) the edge shape, (ii) the location along the microchannel, and (iii) the length of the monolithic plugs within glass microchips. The addition of hydroquinone, a polymerization inhibitor, to the prepolymerization mixture was beneficial for achieving local and robust incorporation of monoliths with sharp edges within microchannels. The monolith length was easily tuned from 160 to 400 µm through simple change in the magnification of the objective and was found to be repeatable (relative standard deviation <7.5%). Further application for on-chip monolith-assisted solid - phase extraction is demonstrated for fluorescently labeled peptide. Both binding and subsequent elution behaviors were found to fully agree with a cation-exchange mechanism in concordance with the presence of phosphate groups at the monolith surface. Graphical abstract In-chip microscope-UV-synthesis of monolithic plugs with sharp edges.

A first overview of textile fibers, including microplastics, in indoor and outdoor environments.

Studies about microplastics in various environments highlighted the ubiquity of anthropogenic fibers. As a follow-up of a recent study that emphasized the presence of man-made fibers in atmospheric fallout, this study is the first one to investigate fibers in indoor and outdoor air. Three different indoor sites were considered: two private apartments and one office. In parallel, the outdoor air was sampled in one site. The deposition rate of the fibers and their concentration in settled dust collected from vacuum cleaner bags were also estimated. Overall, indoor concentrations ranged between 1.0 and 60.0 fibers/m3. Outdoor concentrations are significantly lower as they range between 0.3 and 1.5 fibers/m3. The deposition rate of the fibers in indoor environments is between 1586 and 11,130 fibers/day/m2 leading to an accumulation of fibers in settled dust (190-670 fibers/mg). Regarding fiber type, 67% of the analyzed fibers in indoor environments are made of natural material, primarily cellulosic, while the remaining 33% fibers contain petrochemicals with polypropylene being predominant. Such fibers are observed in marine and continental studies dealing with microplastics. The observed fibers are supposedly too large to be inhaled but the exposure may occur through dust ingestion, particularly for young children.

Site-specific immobilisation of gold nanoparticles on a porous monolith surface by using a thiol-yne click photopatterning approach.

A monolith surface with alkyne functionality was reacted with cysteamine through radical-mediated thiol-yne addition reaction providing a hydrophilic and chelating interface. Photochemical initiation affords spatial control over the reaction site and further site-specific immobilisation of gold nanoparticles.

Capillary columns for reversed-phase CEC prepared via surface functionalization of polymer monolith with aromatic selectors.

Macroporous crosslinked organic polymers based on N-acryloxysuccinimide (NAS) and ethylene dimethacrylate (EDMA) were prepared in the confines of 75 µm id fused-silica capillaries by photoinitiated free radical copolymerization in the presence of 2-2'-azobisisobutyronitrile as initiator and toluene as porogen. Monoliths with good mechanical strength, large porosity as well as surface reactive sites (succinimide leaving groups) could be obtained. Nucleophilic aromatic derivatives, namely benzylamine, phenylbutylamine and naphthylamine were grafted on the monolith surface to introduce π-conjugated ligands to develop particular selectivity. Successful achievement of the post-copolymerization functionalization was ascertained on the basis of in situ chemical characterization by means of Raman spectroscopy. Electrochromatographic properties of π-functionalized poly(NAS-co-EDMA) regarding alkylbenzenes, polycyclic aromatic hydrocarbons, anilines and phenols were evaluated in terms of retention, selectivity and resolution. The as-designed monolithic columns exhibited π-π interaction in addition to hydrophobic interaction due to the aromatic and non-polar nature of the surface-grafted aromatic selectors. One of the major results of this study is that monolithic columns with mixed selectivity providing high potentiality for the separation of solutes with varied chemical structure variation can be obtained by the surface grafting of the appropriate selector. Herein, an example is given for the phenylbutylamine functionalized poly(NAS-co-EDMA) where the butyl and phenyl fragments afford enhanced hydrophobic and π-selectivity, respectively.

Zwitterionic polymeric monoliths for HILIC/RP mixed mode for CEC separation applications.

Polymer-based monoliths with zwitterionic surface character were synthesized in capillary columns following a two-step approach to provide versatile electrochromatographic stationary phases exhibiting potentiality of both hydrophilic interaction and RP separation modes. UV-initiated free radical copolymerization of N-acryloxysuccinimide and ethylene dimethacrylate was performed using azobisisobutyronitrile as initiator and toluene as porogen. One of the originalities of this approach relies on the dual role of the N-acryloxysuccinimide monomer that is successively used during the preparation protocol to first covalently graft chromatographic selectors on the monolith surface via simple nucleophilic substitution reaction and then to generate negative charges through hydrolysis of remaining N-hydroxysuccinimide units. In this respect, the grafting of hexyldiamine affords potential cationic surface charges. It is shown that it is possible to tune, controlling the pH of the mobile phase, the intensity and direction of the generated EOF. Moreover, the nature of the interfacial interaction process responsible for the observed separations is well governed by the composition of the mobile phase. Polymer backbone hydrophilization is proposed as an efficient way to improve the HILIC behavior of poly(N-acryloxysuccinimide-co-ethylene dimethacrylate) based monolithic CEC columns together with the grafting of an alkyldiamine incorporating a shorter aliphatic segment.

Functionalization of macroporous organic polymer monolith based on succinimide ester reactivity for chiral capillary chromatography: a cyclodextrin click approach.

Macroporous cross-linked organic polymer based on N-acryloxysuccinimide (NAS) and ethylene dimethacrylate (EDMA) was prepared inside 75 µm id fused silica capillary as a functionalizable monolithic stationary phase for chromatographic applications. Succinimide groups on the monolith surface provide reactive sites able to react readily through standard electrophile-nucleophile chemistry. Propargylamine was used to prepare alkyne functionalized poly(NAS-co-EDMA). Onto this azido-reactive polymer surface was grafted ß-cyclodextrin (CD) via a triazole ring utilizing the copper(I)-catalyzed 1,3-dipolar cyclo-addition reaction. Chemical characterization was performed in situ after each synthetic step by means of Raman spectroscopy. Good enantioseparations of flavanone enantiomers, chosen as test chiral compound, were achieved under reversed phase conditions by both capillary electrochromatography and nano-liquid chromatography (nano-LC) techniques. These results demonstrate the potentiality and usefulness of click chemistry in the preparation of ß-CD containing chiral organic polymer monolith.

CEC separation of aromatic compounds and proteins on hexylamine-functionalized N-acryloxysuccinimide monoliths.

Reactive organic polymer monoliths were prepared in fused-silica capillaries by UV-initiated free radical polymerization of N-acryloxysuccinimide (NAS) as reactive monomer, ethylene dimethacrylate as crosslinker, azobisisobutyronitrile as initiator, and toluene as porogen. In a second synthetic step, chemical derivatization of the activated-ester moieties was performed in situ through alkylation reaction with alkylamines to afford monolithic stationary phases with potential reversed-phase properties. A correlation between the synthesis conditions--composition of the reactive solution--chemical characteristics of the reactive polymer monoliths--nitrogen/NAS content--and the reversed-phase separation properties of the functionalized monolithic columns--selectivity towards homologous series of akylbenzenes--was clearly established. This finding offers the possibility of adjusting the experimental conditions with respect to the target applications. The monolithic stationary phases with optimized chemical and porous structures were used for the CEC separation of alkylbenzenes, phenols, anilines, organic acids, amino acids, and proteins. The data indicate that depending on the nature of the analytes (charge, hydrophobic/hydrophilic balance, size) reversed-phase or mixed modes may account for the observed separation.

Supramolecular interactions between beta-cyclodextrin and hydrophobically end-capped poly(ethylene glycol)s: a quartz crystal microbalance study.

In this study, the supramolecular interactions occurring between beta-cyclodextrin-based surfaces and macromolecular chains modified at one end with naphthyl, adamantyl, or phenyladamantyl hydrophobic groups were investigated by means of a quartz crystal microbalance. beta-Cyclodextrin-functionalized gold electrodes were obtained through the amide-coupling reaction between mono-6-deoxy-6-amino-beta-cyclodextrin and 11-mercaptoundecanoic acid self-assembled monolayer allowing the reproducible preparation of densely grafted surfaces with host properties. The interaction data obtained for the three different modified poly(ethylene glycol)s are in good agreement with our previous studies performed by high performance liquid chromatography and surface plasmon resonance. This evidences that the driving force for the supramolecular interaction is based on the inclusion of the hydrophobic terminal group of the chains within the cyclodextrin cavities. The reversibility of the inclusion process was proven through the regeneration of the original host properties of the sensing surfaces using sodium dodecylsulfate as a competitor for the desorption of the poly(ethylene glycol) chains.

In situ functionalization of N-acryloxysuccinimide-based monolith for reversed-phase electrochromatography.

Capillary electrochromatography (CEC) monolithic columns were prepared following a two-step synthetic pathway based on (i) UV-induced in situ radical polymerization of N-acryloxysuccinimide (NAS) and ethylene dimethacrylate (EDMA) and (ii) in situ functionalization of the NAS-containing monolithic matrix with various alkylamines. The first synthetic step was performed using toluene as a porogenic solvent. The successful grafting of the alkylamines onto the reactive matrix was confirmed on the basis of qualitative analysis of Raman spectra recorded before and after the chemical modification step. All the electrochromatographic results indicate a strong dependence of the retention, efficiency and selectivity of the monolithic columns on small variations of mobile phase composition and nature of the grafted aliphatic selector in agreement with the typical reversed-phase behaviour. Van Deemter plots for a series of alkylbenzene homologues injected on a column bearing hexyl-segments as side chains are also presented.

DNA immobilisation procedures for surface plasmon resonance imaging (SPRI) based microarray systems.

Two different surface chemistries have been studied for the development of surface plasmon resonance imaging (SPRI) based DNA microarray affinity sensors: (1) 11-mercaptoundecanoic acid-poly(ethylenimine) (MUA-PEI) and (2) dextran procedures. The MUA-PEI method consists of assembling a multilayer on the basis of electrostatic interactions formed with: 11-mercaptoundecanoic acid (MUA), poly(ethylenimine) (PEI) and extravidin layers. The dextran procedure involves assembling a multilayer formed with 11-mercaptoundecanol, dextran and streptavidin layers, which are linked by covalent bonds. The oligonucleotide probes are immobilised onto the sensor surface as spots forming a matrix 14x14, which is spotted by a robot, while the target sequences are free in solution. The system allows the interaction (hybridisation) monitoring, in real-time and in parallel, of unlabeled oligonucleotide solution targets to oligonucleotide probes immobilised on a 196 spots matrix. Using oligonucleotides as probes and targets, both functionalised surfaces have been evaluated in view of their application to the diagnosis of gene mutations involved in human diseases. In particular, we demonstrate the ability to detect, in parallel, several mutations causing human cystic fibrosis (CF), which lie within exon 10 of the human cystic fibrosis transmembrane conductance regulator (CFTR) gene. The immobilised probes were complementary to sequences corresponding the mutant or wild type alleles. Two deletions of three bases (DeltaF508 and DeltaI507) and four single nucleotide polymorphisms (M470V, Q493X, V520F and 1716 G>A) were investigated. In both functionalised surfaces, the system showed the capacity to discriminate normal and mutant sequences differing by a single base.