Le nuove frontiere per la (nano)elettronica

Il notevole processo di miniaturizzazione dei componenti elettronici ha rivoluzionato il nostro modo di vivere, la nostra quotidianità, come ci rapportiamo col mondo e le persone che ci circondano. Oggi la presenza dei circuiti integrati non si limita più ai computer ma si estende a smartphone, orologi ed elettrodomestici. Viviamo in un mondo connesso ed in continua evoluzione. Tali avanzamenti sono stati finora possibili grazie ad un approccio "classico", partendo da un campione di silicio e migliorando le tecniche litografiche impiegate per la sua lavorazione. Ma sarà così ancora per le prossime decadi? Ebbene una serie di limitazioni fisiche e tecnologiche si addensano oggi come nubi all'orizzonte delle attuali tecnologie, rendendo sempre più difficile continuare questo trend. Allo stesso tempo, però, emergono nuovi paradigmi ed architetture sfruttando materiali innovativi ed ulteriori gradi di libertà e fenomeni fisici. Di seguito verranno introdotti i concetti alla base di nanoelettronica, elettronica molecolare e spintronica, saranno discussi alcuni conseguimenti chiave ed infine si accennerà alle prospettive aperte dalla ricerca sulla computazione quantistica

Miniaturized Sensors for Detection of Ethanol in Water Based on Electrical Impedance Spectroscopy and Resonant Perturbation Method - A Comparative Study

The development of highly sensitive, portable and low-cost sensors for the evaluation of ethanol content in liquid is particularly important in several monitoring processes, from the food industry to the pharmaceutical industry. In this respect, we report the optimization of two sensing approaches based on electrical impedance spectroscopy (EIS) and complementary double split ring resonators (CDSRRs) for the detection of ethanol in water. Miniaturized EIS sensors were realized with interdigitated electrodes, and the ethanol sensing was carried out in liquid solutions without any functionalization of the electrodes. Impedance fitting analysis, with an equivalent circuit over a frequency range from 100 Hz to 1 MHz, was performed to estimate the electric parameters, which allowed us to evaluate the amount of ethanol in water solutions. On the other hand, complementary double split ring resonators (CDSRRs) were optimized by adjusting the device geometry to achieve higher quality factors while operating at a low fundamental frequency despite the small size (useful for compact electronic packaging). Both sensors were found to be efficient for the detection of low amounts of ethanol in water, even in the presence of salts. In particular, EIS sensors proved to be effective in performing a broadband evaluation of ethanol concentration and are convenient when low cost is the priority. On the other end, the employment of split ring resonators allowed us to achieve a very low limit of detection of 0.2 v/v%, and provides specific advantages in the case of known environments where they can enable fast real-time single-frequency measurements

Bioinspired Materials for Sensor and Clinical Applications: Two Case Studies

The growing interest in bio-inspired materials is driven by the need for increasingly targeted and efficient devices that also have a low ecological impact. These devices often use specially developed materials (e.g., polymers, aptamers, monoclonal antibodies) capable of carrying out the process of recognizing and capturing a specific target in a similar way to biomaterials of natural origin. In this article, we present two case studies, in which the target is a biomolecule of medical interest, in particular, alpha-thrombin and cytokine IL-6. In these examples, different biomaterials are compared to establish, with a theoretical-computational procedure known as proteotronics, which of them has the greatest potential for use in a biodevice

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

Gas sensing technologies -- status, trends, perspectives and novel applications

The strong, continuous progresses in gas sensors and electronic noses resulted in improved performance and enabled an increasing range of applications with large impact on modern societies, such as environmental monitoring, food quality control and diagnostics by breath analysis. Here we review this field with special attention to established and emerging approaches as well as the most recent breakthroughs, challenges and perspectives. In particular, we focus on (1) the transduction principles employed in different architectures of gas sensors, analysing their advantages and limitations; (2) the sensing layers including recent trends toward nanostructured, low-dimensional and composite materials; (3) advances in signal processing methodologies, including the recent advent of artificial neural networks. Finally, we conclude with a summary on the latest achievements and trends in terms of applications.Comment: arXiv admin comment: This version has been removed by arXiv administrators as the submitter did not have the rights to agree to the license at the time of submissio

Optimization of SAW Sensors for Nanoplastics and Grapevine Virus Detection

In this work, we report the parametric optimization of surface acoustic wave (SAW) delay lines on Lithium niobate for environmental monitoring applications. First, we show that the device performance can be improved by acting opportunely on geometrical design parameters of the interdigital transducers such as the number of finger pairs, the finger overlap length and the distance between the emitter and the receiver. Then, the best-performing configuration is employed to realize SAW sensors. As aerosol particulate matter (PM) is a major threat, we first demonstrate a capability for the detection of polystyrene particles simulating nanoparticulates/nanoplastics, and achieve a limit of detection (LOD) of 0.3 ng, beyond the present state-of-the-art. Next, the SAW sensors were used for the first time to implement diagnostic tools able to detect Grapevine leafroll-associated virus 3 (GLRaV-3), one of the most widespread viruses in wine-growing areas, outperforming electrochemical impedance sensors thanks to a five-times better LOD. These two proofs of concept demonstrate the ability of miniaturized SAW sensors for carrying out on-field monitoring campaigns and their potential to replace the presently used heavy and expensive laboratory instrumentation

Organ-on-chip

Lo sviluppo di nuovi farmaci è un processo lungo, costoso ed attualmente poco efficiente. La causa di questa scarsa efficienza risiede, principalmente, nella scarsa efficienza ed accuratezza delle attuali metodologie di ricerca preclinica, basate su colture cellulari bidimensionali e modelli animali che non sono sufficientemente predittive degli effetti sull'uomo. Oggi lo sviluppo di piattaforme microfisiologiche organon-chip fornisce un nuovo approccio, più efficace, per la ricerca farmacologica e biomedica al fine di migliorare la comprensione dei meccanismi fisiopatologici coinvolti e di sviluppare nuove terapie più efficaci ed eventualmente personalizzate. Queste piattaforme miniaturizzate consentono di investigare sia aspetti collegati alla somministrazione e rilascio dei farmaci che la presenza di effetti di tossicità anche collegati al loro metabolismo. Per tali motivi il settore ha raccolto notevole interesse

Towards pancreatic cancer diagnosis using EIS biochips

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