Paolo Scopece

Highly Luminescent Metal–Organic Frameworks Through Quantum Dot Doping

The incorporation of highly luminescent core-shell quantum dots (QDs) within a metal-organic framework (MOF) is achieved through a one-pot method. Through appropriate surface functionalization, the QDs are solubilized within MOF-5 growth media. This permits the incorporation of the QDs within the evolving framework during the reaction. The resulting QD@MOF-5 composites are characterized using X-ray fluorescence, cross-sectional confocal microscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and small-angle X-ray scattering. The synergistic combination of luminescent QDs and the controlled porosity of MOF-5 in the QD@MOF-5 composites is harnessed within a prototype molecular sensor that can discriminate on the basis of molecular size.

Conical nanopore membranes: solvent shaping of nanopores

We have undertaken a systematic investigation of the influence of ethanol on the shape of conical pores produced by the track-etch technique in poly(ethylene terephthalate) films. We have found that the cone angle of the conical nanopore generated is dependent on the amount of ethanol present in an alkaline etching solution. By varying the percentage of ethanol in the etch solution, precise control over the geometry of the conical nanopore and nanomaterials templated within these pores can be attained. We prove this by plating gold nanocones within the various conical nanopores prepared, dissolving the membrane to liberate the nanocones, and imaging the nanocones using scanning electron microscopy. The results of these investigations are reported here.

Dynamic Control of MOF‐5 Crystal Positioning Using a Magnetic Field

Paolo alcaro , * F rancois F Normandin , Masahide akahashi , T Paolo Scopece , Heinz Amenitsch , Stefano Costacurta , Cara M. Doherty , Jamie S. Laird , Matthew D. H. Layabio , F Lisi , Anita J. Hill , and Dario Buso *

Lead(II) uptake by aluminium based magnetic framework composites (MFCs) in water

The recent combination of Metal-Organic Frameworks (MOFs) and magnetic nanoparticles has shown their potential as a composite material in practical applications including drug delivery, catalysis and pollutant sequestration. Here, we report for the first time the preparation of a robust magnetic nanocomposite material based on an aluminium MOF (MIL-53) and iron oxide nanoparticles for the uptake of lead(II) ions. Different aminofunctionalized MIL-53 MOFs were prepared by increasing the 2-aminoterephthalic/terephthalic acid ratio. The composite materials were tested to determine the sequestration capability of heavy metals from various solvents (methanol, DMSO and water), pH (2, 7, 12) and a range of Pb(II) concentrations (10–8000 ppm). The magnetic composite based on MIL-53 showed remarkable capacity to sequester Pb(II) ions from water (up to 492.4 mg g−1 of composite), the highest recorded for a MOF sorbent system to date. While the MOF played a crucial role in the efficient heavy metal uptake, the magnetic nanoparticles allowed the prompt collection of the sorbent from solution. The triggered release of Pb(II) was investigated using an alternating magnetic field. The exceptional adsorption capacity and the response to the magnetic field make this class of innovative functional material a promising candidate for environmental remediation technologies.

Iron(II) and iron(III) determination by potentiometry and ion-exchange voltammetry at ionomer-coated electrodes

This paper examines the possibility to combine potentiometric and voltammetric measurements, both performed at ionomer coated glassy carbon electrodes, in order to determine the concentration and gain information on the redox state of electroactive ions even when they are present at trace (submicromolar) concentration levels. As a model case, the speciation of iron(II) and iron(III) is studied both for the cations Fe 2+ and Fe 3+ and for the anions Fe(CN)6 4− and Fe(CN)6 3− . For the first situation, electrodes coated with Nafion are employed while for the latter electrodes coated with the anion exchanger Tosflex are examined. The ratios between oxidised and reduced species are measured at trace levels thanks to the ion-exchange preconcentration capabilities of the coatings. Relevant equations ruling the potentiometric responses at the coated electrodes have been derived by proper adjustment of the Nernst equation. Ion-exchange voltammetry at the coated electrodes allowed the measurement of parameters, such as ion-exchange distribution coefficients, which are relevant for the experimental testing of the suitability of these equations. Voltammetry at the coated electrodes allowed also the sensitive determination of the total concentration of both ions of the same redox couple. The applicability of the method for practical purposes has been checked determining redox potential and concentration profiles for iron and reduced sulphur species in the pore-waters of sediments of the lagoon of Venice, Italy.

Method for Optimizing Coating Properties Based on an Evolutionary Algorithm Approach

In industry as well as many areas of scientific research, data collected often contain a number of responses of interest for a chosen set of exploratory variables. Optimization of such multivariable multiresponse systems is a challenge well suited to genetic algorithms as global optimization tools. One such example is the optimization of coating surfaces with the required absolute and relative sensitivity for detecting analytes using devices such as sensor arrays. High-throughput synthesis and screening methods can be used to accelerate materials discovery and optimization; however, an important practical consideration for successful optimization of materials for arrays and other applications is the ability to generate adequate information from a minimum number of experiments. Here we present a case study to evaluate the efficiency of a novel evolutionary model-based multiresponse approach (EMMA) that enables the optimization of a coating while minimizing the number of experiments. EMMA plans the experiments and simultaneously models the material properties. We illustrate this novel procedure for materials optimization by testing the algorithm on a sol-gel synthetic route for production and optimization of a well studied amino-methyl-silane coating. The response variables of the coating have been optimized based on application criteria for micro- and macro-array surfaces. Spotting performance has been monitored using a fluorescent dye molecule for demonstration purposes and measured using a laser scanner. Optimization is achieved by exploring less than 2% of the possible experiments, resulting in identification of the most influential compositional variables. Use of EMMA to optimize control factors of a product or process is illustrated, and the proposed approach is shown to be a promising tool for simultaneously optimizing and modeling multivariable multiresponse systems.

PANNA project --- plasma and nano for new age soft conservation. development of a full-life protocol for the conservation of cultural heritage

EU PANNA project started on November 2011 and aims at integrating a novel atmospheric plasma technique for surface cleaning and two innovative coating typologies (self-diagnostic protective coatings and identification marker coating) in a full-life protocol spanning surface cleaning, deposition of coatings and their complete removal. The validation of the protocol will be achieved through the cooperation between conservation scientists and technological companies. In the project, the development and testing of the protocol will be performed on two categories of substrates: metals (bronze and silver) and stone and stone-like materials (limestone, sandstone and wall paintings). The development will be performed on laboratory prepared samples (dummy or replica or mock ups) and also on real objects.

An Electrochemical Sensor for Trace Inorganic Arsenic Based on Nanoelectrode Ensembles

The results of a study on the determination of trace levels of arsenic with nano-electrode ensembles (NEEs) are reported. The method is characterized by detection limit as low as 5 ng/L (65 pM) after 3 min preconcentration at −0.4 V. NEEs were applied to trace As analysis in real samples such as certified seawater samples.

Nanoroughness, Surface Chemistry and Drug Delivery Control by Atmospheric Plasma Jet on Implantable Devices

Implantable devices need specific tailored surface morphologies and chemistries to interact with the living systems or to actively induce a biological response also by the release of drugs or proteins. These customized requirements foster technologies that can be implemented in additive manufacturing systems. Here, we present a novel approach based on spraying processes that allow to control separately topographic features in the submicron range (∼60 nm to 2 μm), ammine or carboxylic chemistry, and fluorophore release even on temperature-sensitive biodegradable polymers such as polycaprolactone (PCL). We developed a two-steps process with a first deposition of 220 nm silica and poly(lactic- co-glycolide) (PLGA) fluorescent nanoparticles by aerosol followed by the deposition of a fixing layer by an atmospheric pressure plasma jet (APPJ). The nanoparticles can be used to create the nanoroughness and to include active molecule release, while the capping layer ensures stability and the chemical functionalities. The process is enabled by a novel APPJ which allows deposition rates of 10-20 nm·s-1 at temperatures lower than 50 °C using argon as the process gas. This approach was assessed on titanium alloys for dental implants and on PCL films. The surfaces were characterized by Fourier transform infrared, atomic force microscopy, and scanning electron microscopy (SEM). Titanium alloys were tested with the preosteoblast murine cells line, while the PCL film was tested with fibroblasts. Cell behavior was evaluated by viability and adhesion assays, protein adsorption, cell proliferation, focal adhesion formation, and SEM. The release of a fluorophore molecule was assessed in the cell growing media, simulating a drug release. Osteoblast adhesion on the plasma-treated materials increased by 20% with respect to commercial titanium alloy implants. Fibroblast adhesion increased by a 100% compared to smooth PCL substrates. The release of the fluorophore by the dissolution of the PLGA nanoparticles was verified, and the integrity of the encapsulated drug model was confirmed.

Electroanalytical Applications of Sensors Basedon Pyrolized Photoresist Carbon Electrodes

Pyrolyzed photoresist carbon electrodes (PPCEs) fabricated by photolithographic micro-fabrication and pyrolysis of the epoxy-based photoresist named SU-8 are applied to electroanalysis. Bismuth-modified PPCEs (Bi-PPCEs) are used in the adsorptive cathodic stripping voltammetry (AdCSV) of Ni(II) and in the speciation of inorganic Cr, while PPEs are used in the cyclic voltammetric (CV) study of bilirubin (BR) in dimethyl sulfoxide.