Ni-rGO Sensor Combined with Human Olfactory Receptor-Embedded Nanodiscs for Detecting Gas-Phase DMMP as a Simulant of Nerve Agents.

Nerve agents are organophosphorus toxic chemicals that can inhibit acetylcholinesterase, leading to paralysis of the nervous system and death. Early detection of nerve agents is important for safety issues. Dimethyl methylphosphonate (DMMP) is widely used as a simulant of nerve agents, and many studies have been conducted using DMMP as a substitute for detecting nerve agents.

Enhanced osteogenic differentiation of human mesenchymal stem cells using size-controlled graphene oxide flakes.

Recently, it has been revealed that the physical microenvironment can be translated into cellular mechanosensing to direct human mesenchymal stem cell (hMSC) differentiation. Graphene oxide (GO), a major derivative of graphene, has been regarded as a promising material for stem cell lineage specification due to its biocompatibility and unique physical properties to interact with stem cells. Especially, the lateral size of GO flakes is regarded as the key factor regulating cellular response caused by GO.

Optorheological Characteristics of Photosynthetic Bacterium Suspension.

Understanding the rheological behavior of materials is of great importance in science. Here, we report a microscopic foundation for optorheology by manipulating the rheological feature through light. A new phenomenon is observed in the photosynthetic bacterial suspension, that the fluid viscosity changes by light-induced electrons.

Comparative Studies on Crystallinity, Thermal and Mechanical Properties of Polyketone Grown on Plasma Treated CVD Graphene.

In this work, we report a facile way to control crystalline structures of polyketone (PK) films by combining plasma surface treatment with chemical vapor deposition (CVD) technique. The crystalline structure of PKs grown on plasma-treated graphene and the resulting thermal and mechanical properties were systematically discussed. Every graphene sheet used in this work was produced by CVD method and the production of PKs having different crystallinity were performed on the O- and N-doped graphene sheets.

Ruthenium Decorated Polypyrrole Nanoparticles for Highly Sensitive Hydrogen Gas Sensors Using Component Ratio and Protonation Control.

Despite being highly flammable at lower concentrations and causing suffocation at higher concentrations, hydrogen gas continues to play an important role in various industrial processes. Therefore, an appropriate monitoring system is crucial for processes that use hydrogen. In this study, we found a nanocomposite comprising of ruthenium nanoclusters decorated on carboxyl polypyrrole nanoparticles (Ru_CPPy) to be successful in detecting hydrogen gas through a simple sonochemistry method.

Aptamer-Functionalized Three-Dimensional Carbon Nanowebs for Ultrasensitive and Free-Standing PDGF Biosensor.

Research on flexible biosensors is mostly focused on their use in obtaining information on physical signals (such as temperature, heart rate, pH, and intraocular pressure). Consequently, there are hardly any studies on using flexible electronics for detecting biomolecules and biomarkers that cause diseases. In this study, we propose a flexible, three-dimensional carbon nanoweb (3DCNW)-based aptamer sensor to detect the platelet-induced growth factor (PDGF), which is an oncogenic biomarker.

Facile Synthesis of CoO-Incorporated Multichannel Carbon Nanofibers for Electrochemical Applications.

Considering their superior electrochemical performances, extensive studies have been carried out on composite nanomaterials based on porous carbon nanofibers. However, the introduction of inorganic components into a porous structure is complex and has a low yield. In this study, we propose a simple synthesis of cobalt-oxide-incorporated multichannel carbon nanofibers (P-Co-MCNFs) as electrode materials for electrochemical applications.

Comparative Study on the Formation and Oxidation-Level Control of Three-Dimensional Conductive Nanofilms for Gas Sensor Applications.

Investment in wearable monitoring systems is increasing rapidly for realizing their practical applications, for example, in medical treatment, sports, and security systems. However, existing wearable monitoring systems are designed to measure a real-time physical signal and abnormal conditions rather than harmful environmental characteristics. In this study, a flexible chemical sensor electrode based on a three-dimensional conductive nanofilm (3D CNF) is fabricated via facile polymerization with temperature control.

Peptide hormone sensors using human hormone receptor-carrying nanovesicles and graphene FETs.

Hormones within very low levels regulate and control the activity of specific cells and organs of the human body. Hormone imbalance can cause many diseases. Therefore, hormone detection tools have been developed, particularly over the last decade.

Fluorine plasma treatment on carbon-based perovskite solar cells for rapid moisture protection layer formation and performance enhancement.

A fluorine plasma-treated carbon electrode is used in HTM-free perovskite solar cells for high efficiency and moisture resistance. The fluorine-treated device with a champion power conversion efficiency (PCE) of 14.86% is achieved with a highly enhanced FF (FF = 0.

Ultrasensitive, Selective, and Highly Stable Bioelectronic Nose That Detects the Liquid and Gaseous Cadaverine.

Field-effect transistor (FET) devices based on conductive nanomaterials have been used to develop biosensors. However, development of FET-based biosensors that allow efficient stability, especially in the gas phase, for obtaining reliable and reproducible responses remains a challenge. In this study, we developed a nanodisc (ND)-functionalized bioelectronic nose (NBN) based on a nickel (Ni)-decorated carboxylated polypyrrole nanoparticle (cPPyNP)-FET that offers the detection of liquid and gaseous cadaverine (CV).

Highly Crystalline Perovskite-Based Photovoltaics via Two-Dimensional Liquid Cage Annealing Strategy.

Rendering a high crystalline perovskite film is integral to achieve superior performance of perovskite solar cells (PSCs). Here, we established a two-dimensional liquid cage annealing system, a unique methodology for remarkable enhancement in perovskite crystallinity. During thermal annealing for crystallization, wet-perovskite films were suffocated by perfluorodecalin with distinctively low polarity, nontoxic, and chemically inert characteristics.

Fabrication of N-doped multidimensional carbon nanofibers for high-performance cortisol biosensors.

Cortisol is an hormone that regulates blood pressure, glucose levels and carbohydrate metabolism in humans. Abnormal secretion of cortisol can cause various symptoms closely linked to psychological and physical health. In this study, high-performance field-effect transistor (FET)-based biosensors for cortisol detection were fabricated from N-doped multidimensional carbon nanofibers.

Synthesis and Electroresponse Activity of Porous Polypyrrole/Silica-Titania Core/Shell Nanoparticles.

Inverted conducting polymer/metal oxide core/shell structured pPPy/SiO-TiO nanoparticles were prepared as electrorheological (ER) materials using sequential experimental methods. The core was synthesized via the low-temperature self-assembly of PPy and SiO materials, and the outer TiO shell was easily coated onto the core part using a sol-gel method and a titanium isopropoxide precursor. Sonication-mediated etching and redeposition were employed to etch out SiO portions from the core part to blend with TiO shells.

Activation of Haa1 and War1 transcription factors by differential binding of weak acid anions in Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, Haa1 and War1 transcription factors are involved in cellular adaptation against hydrophilic weak acids and lipophilic weak acids, respectively. However, it is unclear how these transcription factors are differentially activated depending on the identity of the weak acid. Using a field-effect transistor (FET)-type biosensor based on carbon nanofibers, in the present study we demonstrate that Haa1 and War1 directly bind to various weak acid anions with different affinities.

Conducting Nanomaterial Sensor Using Natural Receptors.

One of the recently emerging topics in biotechnology is natural receptors including G protein-coupled receptors, ligand-gated ion channels, enzyme-linked receptors, and intracellular receptors, due to their molecular specificity. These receptors, other than intracellular receptors, which are membrane proteins expressed on the cell membrane, can detect extracellular stimuli. Many researchers have utilized cells with natural receptors embedded in the cellular membrane for human sense-mimicking platforms based on electrochemical impedance spectroscopy, quartz crystal microbalances, surface plasmon resonance, and surface acoustic waves.

Facile synthesis of size-controlled FeO nanoparticle-decorated carbon nanotubes for highly sensitive HS detection.

Hydrogen sulfide (HS) is one of the most plentiful toxic gases in a real-life and causes a collapse of the nervous system and a disturbance of the cellular respiration. Therefore, highly sensitive and selective HS gas sensor systems are becoming increasingly important in environmental monitoring and safety. In this report, we suggest the facile synthesis method of the FeO particles uniformly decorated on carbon nanotubes (FeO@CNT) to detect HS gas using oxidative co-polymerization (pyrrole and 3-carboxylated pyrrole) and heat treatment.

Multidimensional Conductive Nanofilm-Based Flexible Aptasensor for Ultrasensitive and Selective HBsAg Detection.

Hepatitis B virus (HBV) infection is a major worldwide health issue causing serious liver diseases, including liver cirrhosis and hepatocellular carcinoma. Monitoring the serum hepatitis B surface antigen (HBsAg) level is pivotal to the diagnosis of HBV infection. In this study, we describe multidimensional conductive nanofilm (MCNF)-based field-effect transistor (FET) aptasensor for HBsAg detection.

High-performance bioelectronic tongue using ligand binding domain T1R1 VFT for umami taste detection.

Numerous efforts have been made to measure tastes for various purposes. However, most taste information is still obtained by human sensory evaluation. It is difficult to quantify a degree of taste or establish taste standard.

Fabrication of Uniform Wrinkled Silica Nanoparticles and Their Application to Abrasives in Chemical Mechanical Planarization.

A simple one-pot method is reported for the fabrication of uniform wrinkled silica nanoparticles (WSNs). Rapid cooling of reactants at the appropriate moment during synthesis allowed the separation of nucleation and growth stages, resulting in uniform particles. The factors affecting particle size and interwrinkle distance were also investigated.

Platinum nanoparticles immobilized on polypyrrole nanofibers for non-enzyme oxalic acid sensor.

Oxalic acid (OA), naturally available in many fruits and vegetables, reacts easily with Ca and Mg ions to produce an insoluble salt. In renal systems, this insoluble salt brings about various renal diseases. As such, the OA excretion level in urine has been utilized as an index parameter in healthcare settings.

Synthesis of Hierarchical Silica/Titania Hollow Nanoparticles and Their Enhanced Electroresponsive Activity.

Wrinkled silica nanoparticle (WSN)-based hollow SiO/TiO nanoparticles (W-HNPs) with hierarchically arrayed internal surfaces were prepared via the combination of sol-gel, TiO coating, and etching of core template techniques. The hierarchical internal surface of W-HNPs was attained using WSNs as a core template. Compared with SiO sphere-templated hollow SiO/TiO nanoparticles (S-HNPs) with flat inner surfaces, W-HNPs displayed distinctive surface areas, TiO loading amounts, and dielectric properties arising from the hierarchical internal surface.

Superfast Room-Temperature Activation of SnO Thin Films via Atmospheric Plasma Oxidation and their Application in Planar Perovskite Photovoltaics.

The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has now exceeded 20%; thus, research focus has shifted to establishing the foundations for commercialization. One of the pivotal themes is to curtail the overall fabrication time, to reduce unit cost, and mass-produce PSCs. Additionally, energy dissipation during the thermal annealing (TA) stage must be minimized by realizing a genuine low-temperature (LT) process.

Ultrasensitive and Selective Organic FET-type Nonenzymatic Dopamine Sensor Based on Platinum Nanoparticles-Decorated Reduced Graphene Oxide.

Dopamine (DA), a catecholamine hormone, is an important neurotransmitter that controls renal and cardiovascular organizations and regulates physiological activities. Abnormal concentrations of DA cause unfavorable neuronal illnesses such as Parkinson's disease, schizophrenia, and attention deficit hyperactivity disorder/attention deficit disorder. However, the DA concentration is exceedingly low in patients and difficult to detect with existing biosensors.