Development of hard X-ray photoelectron spectroscopy in liquid cells using optimized microfabricated silicon nitride membranes.

We present first hard X-ray photoelectron spectroscopy (HAXPES) results of aqueous salt solutions and dispersions of gold nanoparticles in liquid cells equipped with specially designed microfabricated thin silicon nitride membranes, with thickness in the 15-25 nm range, mounted in a high-vacuum-compatible environment. The experiments have been performed at the HAXPES endstation of the GALAXIES beamline at the SOLEIL synchrotron radiation facility. The low-stress membranes are fabricated from 100 mm silicon wafers using standard lithography techniques.

Multimaterial Digital-Light Processing of Metal-Organic Framework (MOF) Composites: A Versatile Tool for the Rapid Microfabrication of MOF-Based Devices.

Patterning Metal-Organic Frameworks (MOFs) is essential for their use in sensing, electronics, photonics, and encryption technologies. However, current lithography methods are limited in their ability to pattern more than two MOFs, hindering the potential for creating advanced multifunctional surfaces. Additionally, balancing design flexibility, simplicity, and cost often results in compromises.

Ethanol Solvation of Polymer Residues in Graphene Solution-Gated Field Effect Transistors.

The persistence of photoresist residues from microfabrication procedures causes significant obstacles in the technological advancement of graphene-based electronic devices. These residues induce undesired chemical doping effects, diminish carrier mobility, and deteriorate the signal-to-noise ratio, making them critical in certain contexts, including sensing and electrical recording applications. In graphene solution-gated field-effect transistors (gSGFETs), the presence of polymer contaminants makes it difficult to perform precise electrical measurements, introducing response variability and calibration challenges.

An ImmunoFET Coupled with an Immunomagnetic Preconcentration Technique for the Sensitive EIS Detection of HF Biomarkers.

We propose a new strategy using a sandwich approach for the detection of two HF biomarkers: tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10). For this purpose, magnetic nanoparticles (MNPs) (MNPs@aminodextran) were biofunctionalized with monoclonal antibodies (mAbs) using bis (sulfosuccinimidyl) suberate (BS) as a cross-linker for the pre-concentration of two biomarkers (TNF-α and IL-10). In addition, our ISFETs were biofunctionalized with polyclonal antibodies (pAbs) (TNF-α and IL-10).

Large area arrays of discrete single-molecule junctions derived from host-guest complexes.

The desire to continually reduce the lower limits of semiconductor integrated circuit (IC) fabrication methods continues to inspire interest in unimolecular electronics as a platform technology for the realization of future (opto)electronic devices. However, despite successes in developing methods for the construction and measurement of single-molecule and large-area molecular junctions, exercising control over the precise junction geometry remains a significant challenge. Here, host-guest complexes of the wire-like viologen derivative 1,1'-bis(4-(methylthio)-phenyl)-[4,4'-bipyridine]-1,1'-diium chloride ([1][Cl]) and cucurbit[7]uril (CB[7]) have been self-assembled in a regular pattern over a gold substrate.

Fast impedimetric immunosensing of IgGs associated with peanut and hazelnut allergens.

Food allergies trigger a variety of clinical adverse symptoms and clinical evidence suggests that the presence of food allergy-related IgG can be helpful in the diagnosis when analyzed at the peptide-epitope level. To validate and select the peptides based on their specificity toward hazelnut or peanut epitopes, the authors of this study developed a silicon-based microchip coupled with click-chemistry bound peptides identified by the Fraunhofer Institute for Cell Therapy and Immunology. Peptides related to hazelnut and peanut allergies were identified and used to develop a silicon-based microchip.

Periodic Arrays of Dopants in Silicon by Ultralow Energy Implantation of Phosphorus Ions through a Block Copolymer Thin Film.

In this work, block copolymer lithography and ultralow energy ion implantation are combined to obtain nanovolumes with high concentrations of phosphorus atoms periodically disposed over a macroscopic area in a p-type silicon substrate. The high dose of implanted dopants grants a local amorphization of the silicon substrate. In this condition, phosphorus is activated by solid phase epitaxial regrowth (SPER) of the implanted region with a relatively low temperature thermal treatment preventing diffusion of phosphorus atoms and preserving their spatial localization.

Immuno field-effect transistor (ImmunoFET) for detection of salivary cortisol using potentiometric and impedance spectroscopy for monitoring heart failure.

Cortisol, a steroid hormone mostly known as "the stress hormone," plays many essential functions in humans due its involvement in several metabolic pathways. It is well-known that cortisol dysregulation is implied in evolution and progression of several chronic pathologies, including cardiac diseases such as heart failure (HF). However, although several sensors have been proposed to date for the determination of cortisol, none of them has been designed for its determination in saliva in order to monitor HF progression.

Selective Antibody-Free Sensing Membranes for Picogram Tetracycline Detection.

As an antibody-free sensing membrane for the detection of the antibiotic tetracycline (TC), a liquid PVC membrane doped with the ion-pair tetracycline/θ-shaped anion [3,3'-Co(1,2-CBH)] ([-COSAN]) was formulated and deposited on a SWCNT modified gold microelectrode. The chosen transduction technique was electrochemical impedance spectroscopy (EIS). The PVC membrane was composed of: the tetracycline/[-COSAN] ion-pair, a plasticizer.

New trends in methyl salicylate sensing and their implications in agriculture.

Methyl salicylate (MeSal) is an organic compound present in plants during stress events and is therefore a key marker for early plant disease detection. It has usually been detected by conventional methods that require bulky and costly equipment, such as gas chromatography or mass spectrometry. Currently, however, chemical sensors provide an alternative for MeSal monitoring, showing good performance for its determination in the vapour or liquid phase.

A Novel Cortisol Immunosensor Based on a Hafnium Oxide/Silicon Structure for Heart Failure Diagnosis.

Assessing cortisol levels in human bodies has become essential to diagnose heart failure (HF). In this work, we propose a salivary cortisol detection strategy as part of an easily integrable lab-on-a-chip for detection of HF biomarkers. Our developed capacitive immunosensor based on hafnium oxide (HfO2)/silicon structure showed good linearity between increasing cortisol concentration and the charge-transfer resistance/capacitance.

A novel electrochemical strategy for NT-proBNP detection using IMFET for monitoring heart failure by saliva analysis.

Heart failure (HF) is a chronic cardiovascular disease that represents main cause of mortality worldwide, particularly for elderly. N-terminal pro-brain natriuretic peptide (NT-proBNP) was identified as the gold standard biomarker for HF diagnosis and therapy monitoring. Presently, saliva analysis represents an emerging and powerful tool for clinical applications and electrochemical immunosensors have shown their potential in Healthcare applications as selective and reliable systems for detecting clinical biomarkers.

Gas Sensors Based on Porous Ceramic Bodies of MSnO Perovskites (M = Ba, Ca, Zn): Formation and Sensing Properties towards Ethanol, Acetone, and Toluene Vapours.

In this work, the gas-sensing functionality of porous ceramic bodies formed by the slip casting technique was studied using perovskite nanoparticles of an MSnO system (M = Ba, Ca, Zn) synthesized by a chemical route. The performance and reliability of the sensitive materials in the presence of different volatile organic compounds (acetone, ethanol, and toluene), and other gases (CO, H and NO) were analysed. The ZnSnO, BaSnO, and CaSnO sensors showed sensitivities of 40, 16, and 8% ppm towards acetone, ethanol, and toluene vapours, respectively.

Polysilicon Microchips Functionalized with Bipyridinium-Based Cyclophanes for a Highly Efficient Cytotoxicity in Cancerous Cells.

The use of micrometric-sized vehicles could greatly improve selectivity of cytotoxic compounds as their lack of self-diffusion could maximize their retention in tissues. We have used polysilicon microparticles () to conjugate bipyridinium-based compounds, able to induce cytotoxicity under regular intracellular conditions. Homogeneous functionalization in suspension was achieved, where the open-chain structure exhibits a more dense packing than cyclic analogues.

Real-Time Edge Neuromorphic Tasting From Chemical Microsensor Arrays.

Liquid analysis is key to track conformity with the strict process quality standards of sectors like food, beverage, and chemical manufacturing. In order to analyse product qualities online and at the very point of interest, automated monitoring systems must satisfy strong requirements in terms of miniaturization, energy autonomy, and real time operation. Toward this goal, we present the first implementation of artificial taste running on neuromorphic hardware for continuous edge monitoring applications.

ZnO Structures with Surface Nanoscale Interfaces Formed by Au, FeO, or CuO Modifier Nanoparticles: Characterization and Gas Sensing Properties.

Zinc oxide rod structures are synthetized and subsequently modified with Au, FeO, or CuO to form nanoscale interfaces at the rod surface. X-ray photoelectron spectroscopy corroborates the presence of Fe in the form of oxide-FeO; Cu in the form of two oxides-CuO and CuO, with the major presence of CuO; and Au in three oxidation states-Au, Au, and Au, with the content of metallic Au being the highest among the other states. These structures are tested towards nitrogen dioxide, ethanol, acetone, carbon monoxide, and toluene, finding a remarkable increase in the response and sensitivity of the Au-modified ZnO films, especially towards nitrogen dioxide and ethanol.

Electrochemical Impedance Spectroscopy Microsensor Based on Molecularly Imprinted Chitosan Film Grafted on a 4-Aminophenylacetic Acid (CMA) Modified Gold Electrode, for the Sensitive Detection of Glyphosate.

A novel electrochemical impedance spectroscopy (EIS) microsensor was implemented for the dosage of traces of glyphosate, in real and synthetic water samples. Molecularly imprinted chitosan was covalently immobilized on the surface of the microelectrode previously modified with 4-aminophenylacetic acid (CMA). The characterization of the resulting microelectrodes was carried out by using cyclic voltammetry measurement (CV), scanning electron microscopy (SEM), and electrochemical impedance spectrometry (EIS).

A silicon nitride ISFET based immunosensor for tumor necrosis factor-alpha detection in saliva. A promising tool for heart failure monitoring.

According to the European statistics, approximately 26 million patients worldwide suffer from heart failure (HF), and this number seems to be steadily increasing. Inflammation plays a central role in the development of HF, and the pro-inflammatory cytokine Tumor necrosis factor-α (TNF-α) represents inflammation gold-standard biomarker. Early detection plays a crucial role for the prognosis and treatment of HF.

VOCs Sensing by Metal Oxides, Conductive Polymers, and Carbon-Based Materials.

This review summarizes the recent research efforts and developments in nanomaterials for sensing volatile organic compounds (VOCs). The discussion focuses on key materials such as metal oxides (e.g.

BPF-Based Thermal Sensor Circuit for On-Chip Testing of RF Circuits.

A new sensor topology meant to extract figures of merit of radio-frequency analog integrated circuits (RF-ICs) was experimentally validated. Implemented in a standard 0.35 μm complementary metal-oxide-semiconductor (CMOS) technology, it comprised two blocks: a single metal-oxide-semiconductor (MOS) transistor acting as temperature transducer, which was placed near the circuit to monitor, and an active band-pass filter amplifier.

Direct Visualization of Current-Stimulated Oxygen Migration in YBaCuO Thin Films.

The past years have witnessed major advancements in all-electrical doping control on cuprates. In the vast majority of cases, the tuning of charge carrier density has been achieved electric field effect by means of either a ferroelectric polarization or using a dielectric or electrolyte gating. Unfortunately, these approaches are constrained to rather thin superconducting layers and require large electric fields in order to ensure sizable carrier modulations.

Exploring Strategies to Contact 3D Nano-Pillars.

This contribution explores different strategies to electrically contact vertical pillars with diameters less than 100 nm. Two process strategies have been defined, the first based on Atomic Force Microscope (AFM) indentation and the second based on planarization and reactive ion etching (RIE). We have demonstrated that both proposals provide suitable contacts.

Ultra-Low Power Sensor Devices for Monitoring Physical Activity and Respiratory Frequency in Farmed Fish.

Integration of technological solutions aims to improve accuracy, precision and repeatability in farming operations, and biosensor devices are increasingly used for understanding basic biology during livestock production. The aim of this study was to design and validate a miniaturized tri-axial accelerometer for non-invasive monitoring of farmed fish with re-programmable schedule protocols. The current device (AE-FishBIT v.

3D impedimetric sensors as a tool for monitoring bacterial response to antibiotics.

The presence of antimicrobial contaminants like antibiotics in the environment is a major concern because they promote the emergence and the spread of multidrug resistant bacteria. Since the conventional systems for the determination of bacterial susceptibility to antibiotics rely on culturing methods that require long processing times, the implementation of novel strategies is highly required for fast and point-of-care applications. Here the development and characterization of a novel label-free biosensing platform based on a microbial biosensor approach to perform antibiotic detection bioassays in diluted solution is presented.

Role of Penetrability into a Brush-Coated Surface in Directed Self-Assembly of Block Copolymers.

High-density and high-resolution line and space patterns on surfaces are obtained by directed self-assembly of lamella-forming block copolymers (BCPs) using wide-stripe chemical guiding patterns. When the width of the chemical pattern is larger than the half-pitch of the BCP, the interaction energy between each BCP domain and the surface is crucial to obtain the desired segregated film morphology. We investigate how the intermixing between BCPs and polymer brush molecules on the surface influences the optimal surface and interface free energies to obtain a proper BCP alignment.