Conventional methods used for the determination of mycotoxins are sensitive and give both qualitative and quantitative information, although they are greatly restricted by long assay time, high cost and limited portability. As a consequence, more rapid, low cost, highly specific and portable methods for detecting these analytes are the focus of a great deal of research. In this perspective, this work describes a label free, simple and reliable method using a specific sequence of ssDNA aptamer for detecting OTA, a toxic fungal metabolite frequently occurring in a variety of foodstuffs and feeds. A piezoelectric (QCM) based biosensor was used for real time monitoring of four ssDNA aptamers-OTA interactions to select the most efficient one. Based on these results, a lab-made plasmonic sensing platform based on sinusoidal gratings was fabricated and functionalized with the most efficient selected aptamer. The sensitivity of the biosensor was found to be dependent on the aptamer immobilization strategy. In the optimized experimental conditions the biosensor was demonstrated to detect down to 0.2 ng/ml of OTA with a LOD of 0.005 ng/ml. These findings sounds very promising to produce high sensitivity, fast and potentially portable biosensors for the detection of OTA in food commodities.

Protein biomarkers are important diagnostic tools for cancer and several other diseases. To be validated in a clinical context, a biomarker should satisfy some requirements including the ability to provide reliable information on a pathological state by measuring its expression levels. In parallel, the development of an approach capable of detecting biomarkers with high sensitivity and specificity would be ideally suited for clinical applications. Here, we performed an immune-based label free assay using Surface Plasmon Resonance (SPR)-based detection of the soluble form of E-cadherin, a cell-cell contact protein that is involved in the maintaining of tissue integrity. With this approach, we obtained a specific and quantitative detection of E-cadherin from a few hundred microliters of serum of breast cancer patients by obtaining a 10-fold enhancement in the detection limit over a traditional colorimetric ELISA.

Multicompartment, spherical microcontainers were engineered through a layer-by-layer polyelectrolyte deposition around a fluorescent core while integrating a ruthenium polyoxometalate (Ru4POM), as molecular motor, vis-à-vis its oxygenic, propeller effect, fuelled upon H2O2 decomposition. The resulting chemomechanical system, with average speeds of up to 25 ?m s-1, is amenable for integration into a microfluidic set-up for mixing and displacement of liquids, whereby the propulsion force and the resulting velocity regime can be modulated upon H2O2-controlled addition.

Glass micromachining is a basic technology to achieve microfluidic networks for lab-on-a-chip applications. Among several methods to microstructure glass, the simplest and most widely applied is wet chemical etching (WE). However, accurate control of the reaction conditions to perform reproducible, fast and safe glass etching is not straightforward. Herein, microwave-assisted WE is demonstrated to intensify the glass etching action under safe working and finely monitored operative conditions and to produce smooth deep channels in short processing times with reduced underetching effects.

The stabilization of fluorous oil droplets in aqueous environment is a critical issue in the preparation of emulsified systems for biomedical applications and in emulsion polymerization technology, due to the extreme immiscibility of aqueous and fluorous phases. We present here a detailed study on the behavior of the hydrophobin HFBI, i.e. a small natural protein endowed with exceptional surface activity, at the interface between aqueous and fluorous phases. HFBI behaves as an efficient and sustainable surfactant at remarkably low concentrations and forms a strong and elastic film at the interface between the two phases. We also show proof-of-concept experiments on the use of HFBI as a surfactant in fluorous oil/water emulsified systems and in microfluidic circuits. This journal is © The Royal Society of Chemistry 2013.

The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed. © 2013 Elsevier B.V.

Films of two fluorinated block copolymers (P(S81-Sz6) and P(S81-Sz11)) were investigated and compared with those of a commercial Teflon-like polymer (PTFE-AF) in the search for novel non-biofouling coatings able to minimize the amount of tear fluid (TF) proteins absorbed on contact lens (CL) surfaces. The adsorption of a solution containing lysozyme, albumin and immunoglobulin G (mimicking the TF composition) on the fluorinated block copolymers was evaluated using a quartz crystal microbalance. P(S81-Sz11) was found to resist protein adsorption more effectively than P(S81-Sz6) and PTFE-AF. The different interaction of P(S81-Sz6) and P(S81-Sz11) with the artificial TF was attributed to creation of a more heterogeneous and moderately hydrophobic surface of the latter polymer film by dynamic contact angle and atomic force microscopy studies. Moreover, deposition of P(S81-Sz11) on a CL-like silicone (PDMS) and a CL thin films demonstrated a protein adsorption reduction of up to 70% relative to pristine PDMS and commercial CL thin films.

Synthetic carriers that mimic "natural lipid-based vesicles" (such as micro/nanovesicles, exosomes) have found broad applications in biomedicine for the delivery of biomolecules and drugs. Remarkable advantages of using synthetic carriers include control over the lipid composition, structure and size, together with the possibility to add tracer molecules to monitor their in situ distribution via fluorescence microscopy. Over the past few years, new methods of vesicles production have been developed and optimized, such as those based on microfluidic techniques. These innovative approaches allow us to overcome the limitations faced in conventional methods of liposome preparation, such as size distribution and polydispersity. Herein, a Microfluidic Hydrodynamic Focusing (MHF) device has been used for the production of lipid-based vesicles with different lipid combinations that resemble natural exosomes, such as phosphatidylcholines (PC), cholesterol (Chol), dicetyl phosphate (DCP) and ceramide (Cer). Thanks to a fine control on fluid manipulation, the MHF device allows preparation of vesicles with controlled size, a relevant feature in the emerging field of carrier-assisted cell-delivery. Interestingly, PC/Chol/Cer vesicles exhibit low polydispersity and high stability up to 45 days. Later, quantum dots (QDs) were successfully embedded in these vesicles through the same preparation process. The development of QD-embedded lipid nanovesicles by MHF devices has never been described previously.

Novel synthetic peptides represent smart molecules for antigen antibody interactions in several bioanalytics applications, from purification to serum screening. Their immobilization onto a solid phase is considered a key point for sensitivity increasing. In this view, we exploited Quartz Crystal Microbalance with simultaneous frequency and dissipation monitoring (QCM-D) with a double aim, specifically, as investigative tool for spacers monolayer assembling and its functional evaluation, as well as high sensitive method for specific immunosorbent assays. The method was applied to pancreatic ductal adenocarcinoma (PDAC) detection by studying the interactions between synthetic phosphorylated and un-phosphorylated alpha-enolase peptides with sera of healthy and PDAC patients. The synthetic peptides were immobilized on the gold surface of the QCM-D sensor via a self-assembled alkanethiol monolayer. The presented experimental results can be applied to the development of surfaces less sensitive to non-specific interactions with the final target to suggest specific protocols for detecting PDAC markers with un-labeled biosensors.

We have developed an integrated microfluidic platform for producing 2-[F-18]-fluoro-2-deoxy-D-glucose(F-18-FDG) in continuous flow from a single bolus of radioactive isotope solution, with constant product yields achieved throughout the operation that were comparable to those reported for commercially available vessel-based synthesisers (40-80%). The system would allow researchers to obtain radiopharmaceuticals in a dose-on-demand setting within a few minutes. The flexible architecture of the platform, based on a modular design, can potentially be applied to the synthesis of other radiotracers that require a two-step synthetic approach, and may be adaptable to more complex synthetic routes by implementing additional modules. It can therefore be employed for standard synthesis protocols as well as for research and development of new radiopharmaceuticals.

Random laser emission is obtained from a fluidic paper-based device realized by conventional soft-lithography techniques on common, flexible, renewable and biocompatible commercial paper. The device is realized exclusively on paper by creating microfluidic porous channels on the cellulose fibres, in which a laser dye (Rhodamine B) can flow by capillarity. The modulation of the random lasing characteristics, in terms of threshold and spectral position, can be tailored by acting on the confinement induced by the lithographic process as well as on the shape and functionalization at the interface of the emitting regions. © 2013 The Royal Society of Chemistry.

Investigations on surface properties of poly(dimethylsiloxane) (PDMS) are justified by its large application ranges especially as coating polymer in fluidic devices. At a micrometer scale, the liquid dynamics is strongly modified by interactions with a solid surface. A crucial parameter for this process is microchannel wettability that can be tuned by acting on surface chemistry and topography. In literature, a number of multi-step, time and cost consuming chemical and physical procedures are reported. Here we selectively modify both wetting and mechanical properties by a single step treatment. Changes of PDMS surface were investigated by X-ray photoelectron spectroscopy and atomic force microscopy and the effects of interface properties on the liquid displacement inside a microfluidic system were evaluated. The negative capillary pressure obtained tailoring the PDMS wettability is believed to be promising to accurately control sample leakage inside integrated lab-on-chip by acting on the liquid confinement and thus to reduce the sample volume, liquid drying as well as cross-contamination during the operation. © 2012 Elsevier B.V. All rights reserved.

We report on a transition in random lasers that is induced by the geometrical confinement of the emitting material. Different dye doped paper devices with controlled geometry are fabricated by soft lithography and show two distinguished behaviors in the stimulated emission: in the absence of boundary constraints, the energy threshold decreases for larger laser volumes showing the typical trend of diffusive nonresonant random lasers, while when the same material is lithographed into channels, the walls act as cavity and the resonant behavior typical of standard lasers is observed. The experimental results are consistent with the general theories of random and standard lasers and a clear phase diagram of the transition is reported. (C) 2013 Optical Society of America