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Abstract: Organic–inorganic nano-hybrids, synthesized by supersonic molecular beams of TiO2 clusters and copper-phthalocyanine (CuPc) molecules, have been used to develop gas-sensing devices. This approach allows tailoring the properties of the synthesized materials and the interface between clusters and organic molecules so that new functional materials with interesting sensing properties are obtained. Two-layer hybrid devices with different architectures have been realized on alumina substrates with gold interdigitated electrodes. The hybrid films show an increase in conductivity up to a factor 6 compared to the pure CuPc depending on the architecture used. The response in terms of changes in conductivity towards non-oxidizing (methanol) species has been tested at different working temperatures. The hybrids show much higher sensitivity and stability with respect to CuPc grown with the same technique and they are already quite responsive at temperatures (75°C) where the nanostructured TiO2 sensors are not at all functional. We ascribe these promising performances to the contribution coming from the n-TiO2–CuPc interfaces generated by the deposition process and we envisage the ability of the supersonic beam approach to produce novel classes of nano-hybrids in a variety of functional nanostructures. [Copyright &y& Elsevier]

High sensitivity zinc oxide (ZnO) tetrapods (TPs) have been functionalized by nucleating cadmium sulphide (CdS) nanoparticles (NPs) directly on their surface with a spotted coverage thanks to an optimized synthesis in dimethylformamide (DMF). The obtained hybrid coupled material has been used to realize a gas sensing device with a highly porous nanostructured network, in which the proper alternation of ZnO-TPs and CdS-NPs gives rise to unconventional chemoresistive behaviours. Among the different tested gases and vapours, the sensor showed a unique fingerprint response-inversion between 300 °C and 400 °C only for nitrogen dioxide (NO2) and acetic acid (CH3COOH). [ABSTRACT FROM AUTHOR]

We report on the correlation between structural and electrical properties of pentacene thin film transistors fabricated by the novel supersonic molecular beam epitaxy (SuMBE) technique. We exploited the ability of SuMBE that, through the control on the molecular precursors in the beam, allows improving the quality in terms of structure and morphology of the semi-conducting thin films compared to the more standard OMBE growth. Different growth conditions were explored to find the better range of beam parameters improving the performance of the TFT device whereas the quality of the films grown was studied by atomic force microscopy. We show that the initial kinetic energy of the pentacene molecule strongly affects both the morphology of the films and the electrical properties of the devices that result to be strongly correlated. With our FET devices prepared, on SiO2/Si and top Au contact, we achieved the very promising field effect mobility larger than 0.5cm2V-1s-1 for films grown at room temperature at a pentacene kinetic energy of about 5.5eV that are characterized by large crystalline grains (>2μm). [Copyright &y& Elsevier]

Foods contaminated by pathogens are responsible for foodborne diseases which have socioeconomic impacts. Many approaches have been extensively investigated to obtain specific and sensitive methods to detect pathogens in food, but they are often not easy to perform and require trained personnel. This work aims to propose a textile organic electrochemical transistor-based (OECT) biosensor to detect L. monocytogenes in food samples. The analyses were performed with culture-based methods, Listeria Precis™ method, PCR, and our textile OECT biosensor which used poly(3,4-ethylenedioxythiophene) (PEDOT):polystyrene sulfonate (PSS) (PEDOT:PSS) for doping the organic channel. Atomic force microscopy (AFM) was used to obtain topographic maps of the gold gate. The electrochemical activity on gate electrodes was measured and related to the concentration of DNA extracted from samples and hybridized to the specific capture probe immobilized onto the gold surface of the gate. This assay reached a limit of detection of 1.05 ng/μL, corresponding to 0.56 pM of L. monocytogenes ATCC 7644, and allowed the specific and rapid detection of L. monocytogenes in the analyzed samples. KEYPOINTS: • Textile organic electrochemical transistors functionalized with a specific DNA probe • AFM topographic and surface potential maps of a functionalized gold gate surface • Comparison between the Listeria monocytogenes Precis™ method and an OECT biosensor., (© 2023. The Author(s).)

Organic electrochemical transistors (OECTs) have demonstrated themselves to be an efficient interface between living environments and electronic devices in bioelectronic applications. The peculiar properties of conductive polymers allow new performances that overcome the limits of conventional inorganic biosensors, exploiting the high biocompatibility coupled to the ionic interaction. Moreover, the combination with biocompatible and flexible substrates, such as textile fibers, improves the interaction with living cells and allows specific new applications in the biological environment, including real-time analysis of plants' sap or human sweat monitoring. In these applications, a crucial issue is the lifetime of the sensor device. The durability, long-term stability, and sensitivity of OECTs were studied for two different textile functionalized fiber preparation processes: (i) adding ethylene glycol to the polymer solution, and (ii) using sulfuric acid as a post-treatment. Performance degradation was studied by analyzing the main electronic parameters of a significant number of sensors for a period of 30 days. RGB optical analysis were performed before and after the treatment of the devices. This study shows that device degradation occurs at voltages higher than 0.5 V. The sensors obtained with the sulfuric acid approach exhibit the most stable performances over time.

The molecular protonation profiles obtained by means of an organic electrochemical transistor, which is used for analysis of molecular products released by blood-derived cultures, contain a large amount of information The transistor is based on the conductive polymer PEDOT:PSS comprising super hydrophobic SU8 pillars positioned on the substrate to form a non-periodic square lattice to measure the state of protonation on secretomes derived from liquid biopsies. In the extracellular space of cultured cells, the number of glycation products increase, driven both by a glycolysis metabolism and by a compromised function of the glutathione redox system. Glycation products are a consequence of the interaction of the reactive aldehydes and side glycolytic products with other molecules. As a result, the amount of the glycation products reflects the anti-oxidative cellular reserves, counteracting the reactive aldehyde production of which both the secretome protonation profile and cancer risk are related. The protonation profiles can be profitably exploited through the use of mathematical techniques and multivariate statistics. This study provides a novel chemometric approach for molecular analysis of protonation and discusses the possibility of constructing a predictive cancer risk model based on the exploration of data collected by conventional analysis techniques and novel nanotechnological devices.

A long-standing goal of nanoelectronics is the development of integrated systems to be used in medicine as sensor, therapeutic, or theranostic devices. In this review, we examine the phenomena of transport and the interaction between electro-active charges and the material at the nanoscale. We then demonstrate how these mechanisms can be exploited to design and fabricate devices for applications in biomedicine and bioengineering. Specifically, we present and discuss electrochemical devices based on the interaction between ions and conductive polymers, such as organic electrochemical transistors (OFETs), electrolyte gated field-effect transistors (FETs), fin field-effect transistor (FinFETs), tunnelling field-effect transistors (TFETs), electrochemical lab-on-chips (LOCs). For these systems, we comment on their use in medicine., Competing Interests: The authors declare no conflict of interest

Environment, biodiversity and ecosystem services are essential to ensure food security and nutrition. Managing natural resources and mainstreaming biodiversity across agriculture sectors are keys towards a sustainable agriculture focused on resource efficiency. Vapour Pressure Deficit (VPD) is considered the main driving force of water movements in the plant vascular system, however the tools available to monitor this parameter are usually based on environmental monitoring. The driving motif of this paper is the development of an in-vivo sensor to monitor the effects of VPD changes in the plant. We have used an in vivo sensor, termed "bioristor", to continuously monitor the changes occurring in the sap ion's status when plants experience different VPD conditions and we observed a specific R (sensor response) trend in response to VPD. The possibility to directly monitor the physiological changes occurring in the plant in different VPD conditions, can be used to increase efficiency of the water management in controlled conditions thus achieving a more sustainable use of natural resources.

The in vivo monitoring of key plant physiology parameters will be a key enabler of precision farming. Here, a biomimetic textile-based biosensor, which can be inserted directly into plant tissue is presented: the device is able to monitor, in vivo and in real time, variations in the solute content of the plant sap. The biosensor has no detectable effect on the plant's morphology even after six weeks of continuous operation. The continuous monitoring of the sap electrolyte concentration in a growing tomato plant revealed a circadian pattern of variation. The biosensor has the potential to detect the signs of abiotic stress, and therefore might be exploited as a powerful tool to study plant physiology and to increase tomato growth sustainability. Also, it can continuously communicate the plant health status, thus potentially driving the whole farm management in the frame of smart agriculture.

Hole collection and transport are crucial physical processes in bulk-heterojunction (BHJ) solar cells, which represent major bottlenecks due to their limitations in power conversion efficiency (PCE). Hence, a more efficient alternative is needed to accept and transport holes to the collection electrode in BHJ solar cells. Here, we bring both electron and hole collection centres close to the point of exciton generation by infiltrating P3HT poly(3-hexylthiophene):PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) blend into a highly porous interconnected p-type NiO-nanoparticle (NiO-np) network, through solvent-assisted grafting. In this study, a hybrid polymer solar cell is demonstrated with a P3HT:PCBM:NiO-np triple-heterojunction active layer which showed greatly improved rectification behaviour, long electron lifetime and generated higher PCE of 4% under AM 1.5 solar illumination with a 75% increase in PCE with respect to the P3HT:PCBM device. The optimum NiO-np amount and active-layer thickness were found to be 2% and 250 nm, respectively.