Nanoplasmonic biosensing approach for endotoxin detection in pharmaceutical field

none7noThe outer membrane of Gram-negative bacteria contains bacterial endotoxins known as Lipopolysaccharides (LPS). Owing to the strong immune responses induced in humans and animals, these large molecules have a strong toxic effect that can cause severe fever, hypotension, shock, and death. Endotoxins are often present in the environment and medical implants and represent undesirable contaminations of pharmaceutical preparations and medical devices. To overcome the limitations of the standard technique, novel methods for early and sensitive detection of LPS will be of crucial importance. In this work, an interesting approach for the sensitive detection of LPS has been realized by exploiting optical features of nanoplasmonic transducers supporting Localized Surface Plasmon Resonances (LSPRs). Ordered arrays of gold nano-prisms and nano-disks have been realized by nanospheres lithography. The realized transducers have been integrated into a simple and miniaturized lab-on-a-chip (LOC) platform and functionalized with specific antibodies as sensing elements for the detection of LPS. Interactions of specific antibodies anchored on protein A-modified sensor chips with the investigated analyte resulted in a spectral shift in the plasmonic resonance peak of the transducers. A good linear relationship between peak shifts and the LPS concentration has been demonstrated for the fabricated nano-structures with a detection limit down to 5 ng/mL. Integration with a proper microfluidic platform demonstrates the possibility of yielding a prototypal compact device to be used as an analytical test for quality determination of pharmaceutical products.openColombelli A.; Primiceri E.; Rizzato S.; Monteduro A.G.; Maruccio G.; Rella R.; Manera M.G.Colombelli, A.; Primiceri, E.; Rizzato, S.; Monteduro, A. G.; Maruccio, G.; Rella, R.; Manera, M. G

Il lavoro in crisi.Trasformazioni del capitalismo e ruolo dei soggetti

Disoccupazione, sottoccupazione, scoraggiamento, precarietà e scarsa qualità sono le facce con cui si presenta il lavoro oggi in Italia; già presenti dagli anni ’80 vengono aggravate dalla crisi finanziaria del 2007. Per capirne le cause è indispensabile da un lato guardare alle trasformazioni del capitalismo industriale in Occidente in conseguenza della globalizzazione e dall'altro alle trasformazioni di una società che diventa più complessa, lacerata da conflitti tra ceti e classi: in essa attori sociali con identità multiple sembrano avere più possibilità di manovra, ma di fatto continuano ad avere molti vincoli. Gli scarsi investimenti, inoltre, non permettono di assorbire le poche persone laureate e diplomate: dunque la qualità del lavoro non corrisponde a quella della forza lavoro.Unemployment, underemployment, discouragement, insecurity and poor quality are the faces with which work appears today in Italy; they are present already in the 80s, they were exacerbated by the financial crisis of 2007. To understand the causes is essential to one side to look at the transformations of industrial capitalism in the West as a result of globalization and on the other to the transformation of a society that becomes more complex, torn by conflicts between classes: in it social actors with multiple identities seem to have more possibilities of maneuver, but in fact they still have many constraints. Underinvestment, also, does not allow to absorb the few people graduates and diplomate: therefore, the quality of work does not match whit the workforce

Nanoparticle Thin Films for Gas Sensors Prepared by Matrix Assisted Pulsed Laser Evaporation

The matrix assisted pulsed laser evaporation (MAPLE) technique has been used for the deposition of metal dioxide (TiO2, SnO2) nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al2O3 substrates. A rather uniform distribution of TiO2 nanoparticles with an average size of about 10 nm and of SnO2 nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG) inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit) towards ethanol and acetone are presented

Magneto-Optical properties of noble-metal nanostructures: functional nanomaterials for bio sensing

Metallic nanostructures supporting Localized Surface Plasmon Resonances (LSPR) are characterized by their unique ability to control and manipulate light at the nanoscale. Noble metal nanostructures, such as gold nanostructures, are demonstrating to exhibit magneto-optic activity in the presence of modulated magnetic field of low intensity in transversal configuration (T-MOKE). Validation of experimental findings was achieved by numerical simulations based on Finite Element Method (FEM) techniques. The developed numerical models allowed studying the combination of the T-MOKE effect with the localized surface plasmon resonance of metal nanoparticles. Numerical optical and magneto-optical spectra provided a deep insight on the physical aspects behind the magneto-optical activity of metal nanostructures strictly related to direction of oscillations electrical dipoles generated in resonance conditions. Additionally the MO signal was characterized as a transducing signal for refractive index sensing in liquid conditions. The outcome is an increase in the limit of detection of magneto optical transducer with respect to traditional plasmonic sensors. A new strategy for magneto-plasmonic sensing based on the use of glass supported -Au nanostructures based on their MO properties has put forward.The authors want to acknowledge G. Montagna and E. Melissano for technical support and the financial support from Italian MIUR through FIRB project RBFR10OAI0 Nanoplasmag. A. G.-M. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (Contract No.MAT2014-58860-P), and the Comunidad de Madrid (Contract No. S2013/MIT-2740).Peer reviewe

Nanoparticle Langmuir-Blodgett Arrays for Sensing of CO and NO2 Gases

Metal oxide sensors with active Fe2O3 and CoFe2O4 nanoparticle arrays were studied. Sensing nanoparticle films from 1, 2, 4 or 7 monolayers were deposited by Langmuir-Blodgett technique. Sensors are formed on the alumina substrates equipped with heating meander. Langmuir-Blodgett layers were heated or UV irradiated to remove the insulating surfactant. Sensing properties were studied towards CO or NO2 gases in concentrations between 0.5 and 100 ppm in mixture with the dry air. Best response values Igas/Iair were obtained with CoFe2O4 device being 3 for 100 ppm of CO and with Fe2O3 device being (38)-1 for 0.5 ppm of NO2

Enhanced gas sensing performance of TiO2 functionalized magneto-optical SPR sensors

9 páginas, 7 figurasPorous TiO2 thin films deposited by glancing angle deposition are used as sensing layers to monitor their sensing capabilities towards Volatile Organic Compounds both in a standard Surface Plasmon Resonance (SPR) sensor and in Magneto-Optical Surface Plasmon Resonance (MO-SPR) configuration in order to compare their sensing performances. Here our results on the enhanced sensing capability of these TiO2 functionalized MO-SPR sensors with Au/Co/Au transducers with respect to traditional SPR gas sensors are presented.This work has been funded by the European Commission (NMP3-SL-2008-214107-Nanomagma), the Spanish MICINN (CSD 2008-00023, MAT 2008-06765-C02-01/NAN, MAT2010-21228), CSIC (JAE fellowship for E. F.-V.) and Comunidad de Madrid (S2009 / MAT – 1726, S2009/TIC – 1476).Peer reviewe

Magnetophotonics for sensing and magnetometry toward industrial applications

Magnetic nanostructures sustaining different types of optical modes have been used for magnetometry and label-free ultrasensitive refractive index probing, where the main challenge is the realization of compact devices that are able to transfer this technology from research laboratories to smart industry. This Perspective discusses the state-of-the-art and emerging trends in realizing innovative sensors containing new architectures and materials exploiting the unique ability to actively manipulate their optical properties using an externally applied magnetic field. In addition to the well-established use of propagating and localized plasmonic fields, in the so-called magnetoplasmonics, we identified a new potential of the all-dielectric platforms for sensing to overcome losses inherent to metallic components. In describing recent advances, emphasis is placed on several feasible industrial applications, trying to give our vision on the future of this promising field of research merging optics, magnetism, and nanotechnology

Da madri a figlie. Le trasformazioni del ruolo delle donne nella famiglia romana. Tra persistenti vincoli sociali e nuove aspirazioni professionali

Negli ultimi 10-20 anni c'è stata una rivoluzione inattesa:l'entrata delle donne nel lavoro per il mercato. Quest'aspetto ha modificato il tradizionale ruolo di casalinga della donna nella famiglia, tipico delle madri, ponendo un problema di politiche sociali che si debbono adeguare a questa nuova condizione femminil

Contraddizioni tra passione per il lavoro e insicurezza

Il capitolo, scritto prevalentemente da Roberto Cavarra, cerca di dare voce ai protagonisti, di mettere in luce le contraddizioni tra passione per il lavoro e insicurezza lavorativa, che in alcuni casi è percepita persino da chi ha un contratto a tempo indeterminato. Mette in relazione le tipologie di lavoro e di carriera, con le diverse tipologie di radio