Paolo Prosposito

Paolo Prosposito
University of Rome Tor Vergata | UNIROMA2 · Department of Industrial Engineering

PhD

About

131
Publications
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1,828
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Introduction
- Synthesis, characterization and application of metal nanoparticles and nanoclusters - Synthesis, characterization and application of graphene oxide quantum dots

Publications

Publications (131)
Conference Paper
We have realized a 3D substrate for surface-enhanced Raman scattering (SERS) sensor with DELIL (Double Exposure Laser Interference Lithography) technique and silver nanoparticles (Ag-NPs) functionalized with an appropriate aptamer. The 3D substrates were obtained by means of soft mold technique in thin layer of sol-gel Ti/TMSPM on silicon substrate...
Article
Full-text available
In the field of research for designing and preparing innovative nanostructured systems, these systems are able to reveal the presence of heavy metals in water samples, and can efficiently and selectively interact with them, allowing for future applications in the field of water remediation. We investigated the electronic and molecular structure, as...
Article
Full-text available
Water pollution caused by hexavalent chromium (Cr(VI)) ions represents a serious hazard for human health due to the high systemic toxicity and carcinogenic nature of this metal species. The optical sensing of Cr(VI) through specifically engineered nanomaterials has recently emerged as a versatile strategy for the application to easy-to-use and chea...
Article
Full-text available
In this work, we investigate by ab initio calculations and optical experiments the sensitivity of graphene quantum dots in their use as devices to measure the presence, and concentration, of heavy metals in water. We demonstrate that the quenching or enhancement in the optical response (absorption, emission) depends on the metallic ion considered....
Article
Full-text available
In the present study, we successfully synthesized N-doped carbon quantum dots (N-CQDs) using a top-down approach, i.e., hydroxyl radical opening of fullerene with hydrogen peroxide, in basic ambient using ammonia for two different reaction times. The ensuing characterization via dynamic light scattering, SEM, and IR spectroscopy revealed a size con...
Article
Full-text available
One of the most important features of striated cardiac muscle is the excitability that turns on the excitation-contraction coupling cycle, resulting in the heart blood pumping function. The function of the heart pump may be impaired by events such as myocardial infarction, the consequence of coronary artery thrombosis due to blood clots or plaques....
Article
Full-text available
Myocardial infarction (MI) is the consequence of coronary artery thrombosis resulting in ischemia and necrosis of the myocardium. As a result, billions of contractile cardiomyocytes are lost with poor innate regeneration capability. This degenerated tissue is replaced by collagen-rich fibrotic scar tissue as the usual body response to quickly repai...
Preprint
In this work, we investigate by ab initio calculations and optical experiments the sensitiv- ity of graphene quantum dots in their use as devices to measure the presence, and concentration, of heavy metals in water. We demonstrate that the quenching or enhancement in the optical response (absorption, emission) depends on the metallic ion considered...
Article
Full-text available
The optical absorption and fluorescence of silver nanoclusters (AgNCs) are widely exploited in many different application fields such as sensors, bio-imaging, drug delivery, etc. In the sensor field, optical devices are highly versatile thanks to their ease of fabrication and low costs and, therefore, are optimal candidates to replace expensive app...
Article
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Heavy metal ions and pesticides are extremely dangerous for human health and environment and an accurate detection is an essential step to monitor their levels in water. The standard and most used methods for detecting these pollutants are sophisticated and expensive analytical techniques. However, recent technological advancements have allowed the...
Article
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In the last decades, much research effort has been invested to develop photonic integrated circuits and the silicon-on-insulator technology was established as reliable platform for highly scalable silicon-based electro-optical modulators. However, the device performance of such devices is restricted by the inherent material properties of silicon. A...
Article
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In this work, the electronic and molecular structure, as well as the morphology, of innovative nanostructured materials whose optical properties respond to the presence of heavy metals in water samples was investigated. In particular, the here discussed silver nanoparticles (NPs) stabilized by a hydrophilic ligand (sodium 3-mercapto-1-propanesulfon...
Conference Paper
In this paper we describe the layout of a Silicon Photonic chip, composed of two different Mach-Zehnder interferometers realized with SOI technology; we report the results obtained from the electromagnetic simulations, that have been performed splitting the MZIs in multiple components to extract the power transmission parameters and we also report...
Article
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The search for semiconducting materials with improved optical properties relies on the possibility to manipulate the semiconductors band structure by using quantum confinement, strain effects, and by the addition of diluted amounts of impurity elements such as Bi. In this study, we explore the possibility to engineer the structural and physical pro...
Article
Silver nanoparticles AgNPs having small (6–8 nm) diameter, were synthesized in water in solutions and left interacting with diluted 3d metals (Co²⁺ or Ni²⁺ ions) solution (1–5 ppm range). The interactions between AgNPs and the metallic ions modify the optical response of the nanoparticles demonstrating their ability to capture metallic ions from wa...
Article
The main purpose of the present work is to analyze a series of Ag nanoparticles (NPs) with different size or ligand functionalization by using X‐ray photoelectron spectroscopy (XPS) and to identify the differences in the band‐shape and energy peak position of photoemission spectra due to the particle dimension. A transmission electron microscopy ch...
Article
Full-text available
This review provides an up-to-date overview on silver nanoparticles-based materials suitable as optical sensors for water pollutants. The topic is really hot considering the implications for human health and environment due to water pollutants. In fact, the pollutants present in the water disturb the spontaneity of life-related mechanisms, such as...
Conference Paper
Full-text available
We designed and produced an integrated silicon photonic circuit, in a single chip with IHP SG25H4_EPIC 0.25 µm technology. A Mach-Zehnder interferometer with an alternative shape for better integration, together with a standard-shape Mach-Zehnder interferometer have been realized. In this work, preliminary results of comparative performance measure...
Conference Paper
Full-text available
The present work is concerned with the investigation of the nonlinear optical response of green emissive CsPbBr 3 nanocrystals, in the form of colloidal dispersions in toluene, synthesized via a room-temperature ligand-assisted supersaturation recrystallization (LASR) method. After carrying out a preliminary characterization via X-Ray Diffraction (...
Article
Full-text available
In this work, hydrophilic silver nanoparticles (AgNPs), bifunctionalized with citrate (Cit) and L-cysteine (L-cys), were synthesized. The typical local surface plasmon resonance (LSPR) at λ max = 400 nm together with Dynamic Light Scattering (DLS) measurements (<2RH> = 8 ± 1 nm) and TEM studies (Ø = 5 ± 2 nm) confirmed the system nanodimension and...
Conference Paper
Full-text available
We have synthesized two-dimensional carbon nanoparticles by oxidative unfolding of C60 fullerene and demonstrated that the selective sensitivity of this material to the presence of Cu²⁺ and Pb²⁺, resulting in variations of the fluorescence intensity and optical absorbance, is related to nanoparticle aggregation processes. This mechanism occurs thro...
Conference Paper
Metal nanoclusters (MNCs) are small aggregates of metal atoms with a mean diameter up to 2 nm, that when excited by electromagnetic radiation of suitable energy present an intense florescence. This optical property can be exploited in many fields such as bioimaging, drug delivery and optical sensing in environmental monitoring. In the present work,...
Preprint
Selective removal of heavy metals from water is a complex topic. We present a theoretical computational approach, supported by experimental evidences, to design a functionalized nanomaterial that is able to selectively capture metallic ions from water in a self-assembling process. A theoretical model is used to map an experimental mixture of Ag nan...
Article
We have synthesized fluorescent and stable silver nanoclusters (AgNCs) capped with poly (methacrylic acid), PMAA, by UV irradiation process. The NCs are well dispersed in aqueous solution and present a uniform distribution with an average dimension of 1.45 ± 0.26 nm. The fluorescence excited at 340 nm was found to be sensitive to the presence of he...
Article
We investigated the response of carbon nanotube/Si photodetectors to nanosecond light pulse using two electrode configurations for photovoltaic and photoconductive operations. When operating in photovoltaic mode, the devices show a linear dependence of the photocurrent as a function of the light pulse energy with rise time of 20 ns. In photoconduct...
Article
Full-text available
CsPbBr 3 and Cs 4 PbBr 6 perovskite powders have been synthesized through a relatively simple low-temperature and low-cost method. Nanocrystalline films have also been deposited from solutions with four different molar compositions of binary salt precursors. Optical absorption, emission and excitation spectra have been performed in the UV-visible s...
Conference Paper
The emission of commercial solid-state lasers is shifted by Raman lasers to selected wavelengths suitable for trace gas detection. Raman lasers can be used in many applications, e.g. differential absorption LIDAR systems (DIAL, Light Detection and Ranging) to detect trace gases like carbon dioxide (CO2), ozone (O3) or water vapor (H2O). Various pum...
Article
Full-text available
Graphene quantum dots (GQDs) have recently been proposed as fluorescent sensors for metal ions dissolved in water. The physical origin of this fluorescence is still not completely clear, therefore further studies on GQDs and their properties are required. Graphene-like quantum dots were prepared by oxidation and unfolding of commercial buckminsterf...
Article
Selective removal of heavy metals from water is a complex topic. We present a theoretical-computational approach, supported by experimental evidences, to design a functionalized nanomaterial that is able to selectively capture metallic ions from water in a self-assembling process. A theoretical model is used to map an experimental mixture of Ag nan...
Conference Paper
Full-text available
The emission of commercial solid-state lasers is shifted by Raman lasers to selected wavelengths suitable for trace gas detection. High power Raman lasers based on Ba(NO3)2, diamond and silicon detect CO2, O3 and H2O. Raman lasers base on the physical effect of stimulated Raman scattering. Two new Raman crystals (spodumene and LuAlO3) are investiga...
Article
A way to produce 3D scaffold is via laser stereolithography. We propose a method of direct laser writing for micro-stereolithography in which we use as light source a low power blue diode laser with a wavelength of 448nm. The material chosen for scaffold fabrication is a polyethylene glycol diacrylate (PEGDA) solution at concentration of 75% in eth...
Article
Metal nanoparticles have attracted more and more attention in the last years due to their unique chemical and physical properties which are very different from the metal bulk material. In particular, when the size of nanoparticles decreases below two nm, nanoparticles can be described as nanoclusters (NCs), and they present peculiar optical propert...
Article
https://authors.elsevier.com/c/1X-LU53WXrBm7 The fluorescence quenching effect of unfolded-fullerene nanoparticles (UFNPs) in the presence of Cu2+ ions in water solution has been investigated for a broad range of fluorophore/quencher concentrations. The experimental Stern-Volmer plot exhibited a nonlinear behaviour with an initial upward curvature...
Article
Optical wavelength multiplexing is a widely used technique in Information and Communication Technology to increase maximum data transmission bandwidth on a single optical fiber. We propose wavelength multiplexing/demultiplexing using optical Ring Resonators (RR) on a silicon photonics circuit for fast timing highly segmented detectors readout. A ca...
Article
Full-text available
Photonic crystals (PCs) show reflectance spectra depending on the geometrical structure of the crystal, the refractive index (neff), and the light incident angle, according to the Bragg-Snell law. Three-dimensional photonic crystals (3D-PCs) composed of polymeric sub-micrometer spheres, are arranged in an ordered face cubic centered (fcc) lattice a...
Article
Full-text available
Silver nanoparticles capped with 3-mercapto-1propanesulfonic acid sodium salt (AgNPs-3MPS), able to interact with Ni2+ or Co2+, have been prepared to detect these heavy metal ions in water. This system works as an optical sensor and it is based on the change of the intensity and shape of optical absorption peak due to the surface plasmon resonance...
Poster
We propose to use wavelength multiplexing on a silicon photonics circuit for highly segmented pixel detectors readout. Many front-end channels can be encoded and transmitted on the same common optical line and subsequently decoded by the back-end optical demultiplexer chip.
Article
Full-text available
A novel type of graphene-like nanoparticle, synthesized by oxidation and unfolding of C60 buckminsterfullerene fullerene, showed multiple and reproducible sensitivity to Cu2+, Pb2+, Cd2+, and As(III) through different degrees of fluorescence quenching or, in the case of Cd2+, through a remarkable fluorescence enhancement. Most importantly, only for...
Article
We have synthesized self-assembled photonic crystals (PCs) based on polystyrene nanospheres having average diameters of 250 nm. Samples were obtained by drop-casting technique and subsequent self-assembly on pre-treated glass substrates to increase the surface wettability. Films showed a very good reflectance band with a maximum at 600 nm. We studi...
Article
Full-text available
A novel type of graphene-like quantum dots, synthesized by oxidation and cage-opening of C60 buckminsterfullerene, has been studied as a fluorescent and absorptive probe for heavy-metal ions. The lattice structure of such unfolded fullerene quantum dots (UFQDs) is distinct from that of graphene since it includes both carbon hexagons and pentagons....
Article
Full-text available
An innovative concept of a low-cost pH optode with working volumes of less than 150 µL is presented. The pH monitoring is based on the color changing effect of pH indicators. The optode includes an RGB color sensor patch TCS34725 from Adafruit, a controllable LED and reactor slides and is addressed by a self-written LabVIEW© software. Utilizing the...
Preprint
A novel type of graphene-like quantum dots, synthesized by oxidation and cage-opening of C60 buckminsterfullerene, has been studied as a fluorescent and absorptive probe for heavy-metal ions. The lattice structure of such unfolded fullerene quantum dots (UFQDs) is distinct from that of graphene since it includes both carbon hexagons and pentagons....
Article
Single Walled Carbon Nanotube/n-Si (SWCNT/n-Si) hetero-junctions have been obtained by depositing SWCNT ultra-thin films on the surface of an n-Si substrate by dry transfer method. The as obtained junctions are photo sensitive in the measured wavelength range (300 nm-1000 nm) and show zero bias responsivity and detectivity values of the order of 1...
Article
Full-text available
We report on synthesis of silver nanoparticles (AgNPs) capped with specific thiol suitable to detect heavy metal ions in water. The sensing mechanism is based on a change of an optical properties of the silver colloids, namely the surface plasmon resonance (SPR) when small amounts of contaminants are present in solution. We detected a specific sens...
Article
The design of reliable biocompatible and biodegradable scaffolds remains one of the most important challenges for tissue engineering. In fact, properly designed scaffolds must display an adequate and interconnected porosity to facilitate cell spreading and colonization of the inner layers, and must release physical signals concurring to modulate ce...
Article
Full-text available
Due their excellent chemo-physical properties and ability to exhibit surface plasmon resonance, silver nanoparticles (AgNPs) have become a material of choice in various applications, such as nanosensors, electronic devices, nanobiotechnology and nanomedicine. In particular, from the environmental monitoring perspective, sensors based on silver nano...
Article
Full-text available
A native isolate of the colonial benthic diatom Staurosirella pinnata was cultivated for biosilica production. The silicified cell walls (frustules) were used as a source of homogeneous and structurally predictable porous biosilica for dye trapping and random laser applications. This was coupled with the extraction of lipids from biomass showing po...
Article
The objective of the present work was the development of a micro-pH meter for the determination of the pH value within bioreactors with a volume of up to 200 μl in total. Two different prototypes of optodes were designed and tested. In a first approach spectroscopic analysis of bromothymol blue in a micro-sized-channel structure was carried out uti...
Article
The present study is focused on the design and fabrication of novel functional 3D-hydrogel scaffolds for regenerative medicine. In order to critically analyzing the effect of the microarchitecture of 3D scaffolds for driving the cellular fate and diffusion of progenitor stem cells we have fabricate a number of scaffolds with different geometry, sti...
Article
Diatoms are unicellular aquatic microalgae possessing amazing self-assembled ordered micro-and nanoporous hierarchical silica cell walls called frustules. The quasi-periodic and highly regular pore patterns on the diatom surface are very attractive for applications based on optical and photonic properties of materials. The present contribution repo...
Article
Full-text available
InP/InGaP surface quantum dots are interesting materials for optical chemical sensors since they present an intense emission at room temperature, whose intensity changes rapidly and reversibly depending on the composition of the environmental atmosphere. We present here their emission properties by time resolved photoluminescence spectroscopy inves...
Conference Paper
The present study is focused on the study of novel 3D hydrogel scaffolds for regenerative medicine. We are studying how shape, geometry, stiffness and in general the mechanical properties of the three dimensional scaffolds affect the mechanism of cellular differentiation. The physical features of the scaffolds, as the biochemical factors, determina...
Article
Abstract InP/InGaP surface quantum dots represent an attractive material for optical chemical sensors since they show a remarkable near infra-red emission at room temperature, whose intensity increases rapidly and reversibly depending on the composition of the environmental atmosphere. We show here their emission properties by time resolved photolu...
Conference Paper
We report on 80 nm diameter mono-dispersed gold nanoparticles ordered along lines by means of soft lithographic method on PEDOT:PSS layers. Silicon based mold engraved with Bragg gratings were employed to accomplish the periodic nanoparticles arrangement on large area surface. The results are promising for an increase of the power conversion effici...
Article
Here, we present a reliable process to deposit transparent conductive films on silicon oxide, quartz, and sapphire using a solid carbon source. This layer consists of partially ordered graphene flakes with a lateral dimension of about 5 nm. The process does not require any catalytic metal and exploits a high current arc evaporation (Φ-HCA) to homog...
Article
Full-text available
We report on numerical simulations of InP surface lateral quantum-dot molecules on In0.48Ga0.52 P buffer, using a model strictly derived by experimental results by extrapolation of the molecules shape from atomic force microscopy images. Our study has been inspired by the comparison of a photoluminescence spectrum of a high-density InP surface quan...
Article
We report the synthesis and photophysical characterization of four 9,10-disubstituted dipheny-lanthracenes with specific modifications of the model backbone which involve both the 9,10 para substituents at the phenyl rings and the substitution with carbon-carbon triple bonds. The effects of such modifications on the photoluminescence and electrolum...
Article
Full-text available
af In this work the possibility to exploit the ability of multiple scattering and localization of light shown by diatom silica shells (frustules) for photoluminescence amplification in a random laser was investigated. To this aim polymethylmethacrylate matrix composite random lasers based on rhodamine B and frustules as gain medium and scatterers,...
Article
The possibility of using electrospinning to deposit, and simultaneously electrically pole, polymeric mats containing nonlinear optical (NLO) molecules is studied. Disperse Red 1 (DR1) chromophore dispersed into polymethyl methacrylate (PMMA) fibers is chosen as test system. Aligned fibers of DR1/PMMA are deposited by means of the rotating collector...
Article
In this paper, we report an experimental procedure for active layer nanostructuring in Dye Sensitized Solar Cells (DSCs) to enhance light harvesting. A Bragg grating has been realized on a high performance commercial photoresist by means of Laser Interference Lithography (LIL) technique. Subsequently this structure has been replicated by a Soft Lit...
Article
Full-text available
We report on numerical simulations of a zincblende InP surface quantum dot (QD) on buffer. Our model is strictly based on experimental structures, since we extrapolated a three-dimensional dot directly by atomic force microscopy results. Continuum electromechanical, bandstructure and optical calculations are presented for this realistic structure,...