The growing global population and the rapid increase in older adults are driving healthcare costs upward. In response, the healthcare system is shifting toward models that enable continuous monitoring of individuals without requiring hospital admission. Advances in sensing technologies, embedded systems, wireless communication, nanotechnology, and device miniaturization have made these smart systems possible. Wearable sensors can monitor physiological indicators and other symptoms, helping to detect unusual or unexpected events. This allows for the provision of timely assistance when it is needed most. This paper outlines the challenges associated with these systems and reviews recent developments in wearable, sensor-based human activity monitoring. The focus is on health monitoring applications, including relevant biomarkers, wearable and implantable sensors, and established sensor technologies currently used in healthcare, as well as future prospects. It also discusses the challenges involved in researching, developing, and applying these sensors. The goal is to promote the widespread use of these sensors in human health monitoring.

In order to reduce environmental pollution and atmospheric CO2 concentration, carbon nanotubes (CNTs) have been extensively studied in the solid phase for their ability to adsorb a wide variety of compounds. However, maximum adsorption capacities were found to be comparable to those obtained with more traditional filtration materials such as activated carbon. Conversely, the functionalization of CNTs in the liquid phase has been of great interest over the years, but with no focus on maximum adsorption capacities. The present work exploits UV-Vis spectroscopy to study the adsorption kinetics of three polyvinyl polymers, poly(1-methyl-3-vinylimidazolium iodide), poly(4-methyl-1-vinyl-1,2,4-triazolium iodide), and poly((3,6-diacetyl)-9-vinyl carbazole), on single-walled CNTs (SWCNTs) dispersed at low concentration in N-methyl-2-pyrrolidone. Exceptionally high adsorption capacities of up to 20 g of polymer per g of SWCNTs were obtained, over an order of magnitude higher than those obtained in solid phase adsorption studies. The equilibrium adsorption capacities were best modeled using Freundlich isotherms with exponents close to 1, suggesting a homogeneous adsorption process controlled by both polymer-SWCNT and polymer-polymer interactions. While many questions remain regarding the drivers of these extremely high adsorption capacities, the current results already open up a wide range of potential applications in CO2 sequestration, air purification and water remediation.

ABSTRACT Organic n‐type polymers usually suffer from relatively low electrical conductivity which hampers their application as an active layer for thermoelectrics. Molecular dopants such as benzimidazol‐2‐yl‐N, N‐dimethylbenzenamine (N‐DMBI) are often employed to improve the polymer's electrical conductivity. It was found that 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) radical can be employed to improve N‐DMBI doping efficiency of a bicomponent blend via hydrogen transfer. Herein, we report on a novel n‐type conjugated polymer with TEMPO radical moieties attached to the side chains, whose conjugated core is formed by two electron‐deficient units, i.e. diketopyrrolopyrrole (DPP) and isoindigo (IID). We show that the electrical conductivity of such TEMPO‐functionalized polymer increases up to 4 orders of magnitude upon blending with N‐DMBI resulting in a power factor of 0.6 µW m−1 K−2. Additionally, a reference polymer without side‐chain TEMPO functionalization was synthesized that did not feature a significant conductivity increase. Our work shows that attaching TEMPO radical units to the side chains of an n‐type conjugated polymer is a suitable strategy to boost the doping efficiency of N‐DMBI. Our findings contribute to the design of novel n‐type conjugated polymers that feature high thermoelectric performances upon blending with a molecular dopant.

Sujets sociétaux, la santé, la médecine, l’environnement, l’alimentation et la sécurité ne sauraient se développer sans l’apport des capteurs chimiques et des biocapteurs, dont les performances ne cessent de s’améliorer en termes de fiabilité et de coût, avec une orientation forte vers la production de dispositifs autonomes connectés à Internet. L’obtention de signaux de transduction résultant de l’interaction d’un analyte avec un capteur, permet l’identification et le dosage d’un composé déterminé. Cela implique le choix de méthodes physiques de mesure adaptées et la réalisation de structures réagissant spécifiquement à différents types d’analytes. Nanotechnologies et nanomatériaux appliqués aux capteurs chimiques et aux biocapteurs décrit et analyse les progrès récents réalisés dans la conception de capteurs intégrant dans leur fabrication des nanostructures comportant des nanomatériaux carbonés (graphène, nanotubes de carbone, carbon quantum dots, etc.) et inorganiques (nanoparticules métalliques, nanocristaux, dichalcogénures de métaux de transition, etc.) associés à des méthodes physiques de détection variées (électrochimiques, piézoélectriques, électroniques, optiques, optoélectroniques, etc.).

Detection of Ribonucleic acids (RNA) is a critical step in the identification of viral or bacterial infections in humans and animals. Reverse transcriptase-polymerase chain reaction (RT-PCR) remains the gold standard, but clustered regularly interspaced short palindromic repeats linked to a Cas endoribonuclease particle (CRISPR/Cas) have recently revolutionized the recognition step of two RNAs, i.e. the CRISPR-RNA (crRNA) and the target, providing a much better selectivity compared to the naked hybridization on which RT-PCR is based. Here, we combine the high efficiency of the CRISPR/Cas13a system with the transduction and amplification capabilities of an electrolyte-gated graphene field-effect transistor (EGGFET) for the detection of specific RNA sequences. In these devices, fabricated on flexible plastic substrates, the active material (reduced graphene oxide, rGO) is deposited by printing and then functionalized with Au nanoparticles decorated with polyU RNA reporter strands. In this system, the CRISPR/Cas13a complex acts as a catalyst: in the presence of a specific RNA target sequence, the enzymatic function is activated and the polyU RNA reporter strands are cleaved from the Au nanoparticles, inducing a loss of negative charges on the rGO layer. This phenomenon leads to measurable changes in the transfer curve of the transistors. These sensors were tested for the detection of a SARS-CoV-2 RNA sequence and showed a linear response in the range of 10-7 - 102 ng.μL-1 with an estimated limit of detection of 10 fM. This work is an important milestone in the development of the next generation of point-of-care RNA sensors.

The accurate detection of bilirubin biomarker is vital for diagnosis of liver diseases. In this study, a novel fieldeffect-transistor sensor (FET) using aminated reduced graphene oxide flakes (GNH) decorated with manganese dioxide (MnO2) as channel material has been introduced. The channel material (GNH/MnO2) was first prepared via in-situ chemical reduction of Mn ions on the aminated reduced graphene oxide flakes, then formulated in ink solution, and finally printed on the channel of the device using extrusion printing method. The results showed the growth of needle-like MnO2 nanostructure (firmly anchored on graphite flakes) which can act as an excellent catalyst for the oxidation reaction of bilirubin in the later sensing tests. Upon the addition of the targeted molecule (bilirubin), the charge neutrality point was significantly shifted when GNH/MnO2 was used as the channel material (+25 mV) whereas this point was just slightly shifted (+0.1 mV) when MnO2 was not introduced. The use of extrusion printing technique has also provided us with a conventional approach to produce low-cost devices with good reproducibility. The as-prepared FET sensors were able to detect bilirubin with a limit of detection (LOD) as low as 10-11 M with good repeatability (relative standard deviation, RSD = 2.64 %). This research has demonstrated the potential application of printable sensing devices integrated with functional nanomaterials as advanced diagnostic tools.

Biomaterials play a crucial role in advancing biosensor technologies for medical, environmental, and food safety applications. This study investigates natural biomaterials, such as food-derived chromophores, cellulose, and peptides, for high-performance biosensors and bioelectronic devices. Chromophores, namely grape anthocyanins, are potential candidates for the development of artificial retinal devices showing light-responsivity at 435 nm, close to the human blue cone photoreceptors (420 nm), and transient photo-current signals of 15 nA/mm2 (20 ms, blue-light pulse). Realized cellulose-silk fibroin (SF:CNCs)-based biodegradable substrates are suitable for flexible and sustainable optoelectronic devices, showing transmittance over 40

This study reports the fabrication and characterization of bipolar, fully printed organic thermoelectric generators on flexible substrates. All fabrication and testing are carried out under ambient conditions, demonstrating the feasibility of low-cost, scalable manufacturing. The thermoelectric performance is evaluated in both flat and bent configurations, revealing a clear enhancement under mechanical deformation. The Seebeck coefficient of a single thermocouple increases from 30 mu V K-1 in the flat state to 38.9 mu V K-1 when bent, while the maximum output power rises from 8.8 to 14.9 nW. The devices also exhibit good stability, retaining approximate to 90% of their output power after 60 days of ambient exposure. These results confirm that fully printed, flexible organic thermoelectric generators are robust and lightweight energy harvesters whose performance improves under mechanical stress, highlighting their potential for real-world, mechanically dynamic applications.

While the usual complementary inverter is composed of a pair of n-type and p-type field-effect transistors, we show that a functional inverter can be made out of p-doped reduced graphene oxide (rGO) transistors, operating in the electrolyte-gated configuration. We developed such devices on flexible polyimide substrates, from the deposition of a water-based home-made formulation of graphene oxide (GO). GO was furtherly turned into rGO by an in situ electroreduction step, able to tune the doping level of the material. We explored the experimental key parameters that control the electrical features of single rGO-transistors involved in the inverter, especially the interplay between gate and drain voltages and we developed a numerical toy-model in order to have a better understanding on the electric behavior of our ambipolar rGO-based inverters. Through the functionalization of the device's channel with a potassium ionophore III membrane, we show the proof of concept of an original rGO-based ion sensor able to detect a certain ion concentration threshold in aqueous media, with a direct numerical or voltage readout method, which is conforming to the emerging field of Chemical Logic, and that is less resources-consuming regarding the integration of such sensors in electronic circuits.

Recently, there has been an increasing interest in the development of wearable sensors for monitoring vitamin C (ascorbic acid) in sweat. These sensors can help assess personal nutritional status, prevent vitamin imbalances, and determine the effectiveness of certain medical treatments. This study presents the first example of non-enzymatic ascorbic acid sensor based on the catalytic activity of printed AuNPs. The three-electrode electrochemical system sensor was fabricated by printing a working and counter-electrode from an AuNP-based ink and a pseudo-reference electrode from a silver ink, on a flexible Kapton (R) substrate. SEM examination of the printed gold layer revealed a highly divided material, which facilitates electron transfer and accelerates the oxidation of ascorbic acid. In vitro amperometry demonstrated a proportional increase in current with ascorbic acid concentration ranging from 10 to 390 mu M, with a sensitivity of 14 mu AmM-1cm-2. The low oxidation potential of +0.2 V vs Ag/AgCl effectively avoided most interfering oxidations. These results pave the way toward evaluation on the body of healthy volunteers, by placing the sensor directly on their skin, for example for tracking the changes in ascorbic acid concentration in sweat when eating Vitamin C tablets or Vitamin C-containing food such as orange juice. The very first results demonstrated good real-time performance in testing in such experimental conditions. This has potential applications in healthcare, not only on skin but also on therapeutic bandages applied to chronic wounds.

In this review, recent advances in the combination of CRISPR–Cas systems with graphene-based electrolyte-gated transistors are discussed in detail. In the first part, the functioning of CRISPR–Cas systems is briefly explained, as well as the most common ways to convert their molecular activity into measurable signals. Other than optical means, conventional electrochemical transducers are also developed. However, it seems that the incorporation of CRISPR/Cas systems into transistor devices could be extremely powerful, as the former provides molecular amplification, while the latter provides electrical amplification; combined, the two could help to advance in terms of sensitivity and compete with conventional PCR assays. Today, organic transistors suffer from poor stability in biological media, whereas graphene materials perform better by being extremely sensitive to their chemical environment and being stable. The need for fast and inexpensive sensors to detect viral RNA arose on the occasion of the COVID-19 crisis, but many other RNA viruses are of interest, such as dengue, hepatitis C, hepatitis E, West Nile fever, Ebola, and polio, for which detection means are needed.

Guanine quadruplexes (G4s) are nucleic acid structures present in diverse regions of the genome, such as telomeres and transcription initiators. Recently, the different biological roles of G4s have been evidenced as well as their role as biomarkers for tumors or viral infections. However, the fast and efficient detection of G4s in complex matrices remains elusive. In this contribution, by using long-scale molecular dynamics simulations, we propose the design of a biosensor based on organic field-effect transistors recognizing G4s. In particular, we show that the interaction of the G4s with the biosensor is translated into a change in the charge density profile, which correlates with the electrical transduction of the signal, thus allowing the detection of the nucleic acid structure. We also provide rules of thumb for the optimization of the design of the device and more generally for the integration of computationally driven design approaches.

.Conductivity and Seebeck coefficient of inkjet-printed PEDOT:PSS thin films were found to depend on the substrate (polyimide, silicon oxide, glass) and electrode (e-beam evaporated vs. inkjet-printed). The printing direction was also found to strongly impact the thermoelectric power factor.

The dissemination of sensors is key to realizing a sustainable, ‘intelligent’ world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g. via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g. printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, ‘intelligent’ world.

Objective: Mask choice is a key parameter in adaptation of ventilation through continuous positive airway pressure i.e. sleep apnea syndrome golden standard treatment. Two parameters of mask poor tolerance are cutaneous over pressure and unintentional leaks. The aim of this study was to create a test bench for masks to compare and localize cutaneous pressure areas, while monitoring leak flow. Methods: The test bench is made of an artificial head on which customs-made pressure sensors were placed. The artificial head and the sensors were developed with various additive manufacturing technologies. Sensors measured electrical capacity variations (%VC) positively correlated with cutaneous pressure. For 4 different masks, different harness tightening conditions were tested. A flowmeter was used to monitor total leaks. Results: When displayed on the nasal bridge of the artificial head, sensors detected tightening conditions: average of + 2%VC when harness was tight. This increase varied according to masks [1; 3]%VC and the sensors position [1.3; 2.2]%VC. Conclusion: This bench test allowed us to compare masks between them. Indeed it allowed us to localize and compare high pressure areas according to the mask. These data could be helpful for physicians and health professionals in the choice of the mask and for manufacturers in the development process

Plants as living organisms, as well as their material-structural components and physiological processes, offer promising elements for developing more sustainable technologies. Previously, we demonstrated that plants could acquire electronic functionality, as their enzymatic activity catalyzes the in vivo polymerization of water-soluble conjugated oligomers. We then leveraged plant-integrated conductors to develop biohybrid energy storage devices and circuits. Here, we extend the concept of plant biohybrids to develop plant-based energy-harvesting devices. We demonstrate plant biohybrids with modified roots that can convert common root exudates, such as glucose, to electricity. To do so, we developed a simple one-step approach to convert living roots to glucose-sensitive electrodes by dipping the root in a solution of the conjugated trimer ETE-S and the enzyme glucose dehydrogenase flavin adenine dinucleotide. The biohybrid device responds to glucose concentrations down to 100 mu M while it saturates at 100 mM. The performance of our approach was compared with a classic mediator-based glucose biosensor functionalization method. While the latter method increases the stability of the sensor, it results in less sensitivity and damages the root structure. Finally, we show that glucose oxidation can be combined with the volumetric capacitance of p(ETE-S)-forming devices that generate current in the presence of glucose and store it in the same biohybrid root electrodes. The plant biohybrid devices open a pathway to biologically integrated technology that finds application in low-power devices, for example, sensors for agriculture or the environment.