Development of an IoT-integrated multiplexed digital PCR system for quantitative detection of infectious diseases.

For rapid detection of the COVID-19 infection, the digital polymerase chain reaction (dPCR) with higher sensitivity and specificity has been presented as a promising method of point-of-care testing (POCT). Unlike the conventional real-time PCR (qPCR), the dPCR system allows absolute quantification of the target DNA without a calibration curve. Although a number of dPCR systems have previously been reported, most of these previous assays lack multiplexing capabilities.

Open-Bandgap Graphene-Based Field-Effect Transistor Using Oligo(phenylene-ethynylene) Interfacial Chemistry.

Organic interfacial compounds (OICs) are required as linkers for the highly stable and efficient immobilization of bioprobes in nanobiosensors using 2D nanomaterials such as graphene. Herein, we first demonstrated the fabrication of a field-effect transistor (FET) via a microelectromechanical system process after covalent functionalization on large-scale graphene by introducing oligo(phenylene-ethynylene)amine (OPE). OPE was compared to various OICs by density functional theory simulations and was confirmed to have a higher binding energy with graphene and a lower band gap than other OICs.

Two-stage amplification of an ultrasensitive MXene-based intelligent artificial eardrum.

We report an artificial eardrum using an acoustic sensor based on two-dimensional MXene (TiCT), which mimics the function of a human eardrum for realizing voice detection and recognition. Using MXene with a large interlayer distance and micropyramid polydimethylsiloxane arrays can enable a two-stage amplification of pressure and acoustic sensing. The MXene artificial eardrum shows an extremely high sensitivity of 62 kPa and a very low detection limit of 0.

Cost-effective method for fabricating carbon nanotube network transistors by reusing a 99% semiconducting carbon nanotube solution.

Carbon nanotubes (CNTs) are one-dimensional materials that have been proposed to replace silicon semiconductors and have been actively studied due to their high carrier mobility, high current density, and high mechanical flexibility. Specifically, highly purified, pre-separated, and solution-processed semiconducting CNTs are suitable for mass production. These CNTs have advantages, such as room-temperature processing compatibility, while enabling a fast and straightforward manufacturing process.

Electrochemical detection of caspase-3 based on a chemically modified M13 phage virus.

Caspase-3, a cysteine-dependent protease, is considered a reliable molecular biomarker for the diagnosis and prognosis of apoptosis-related diseases. In this study, we demonstrated a phage-based electrochemical biosensor for the evaluation of cell apoptosis by the sensitive and specific detection of caspase-3. Specifically, for screening of affinity peptide-displayed phages, phage display was performed using M13 phage libraries (cyclic forms of peptides), and we identified potential affinity peptide-displayed phage clones with the sequence CPTTMWRYC.

A phage virus-based electrochemical biosensor for highly sensitive detection of ovomucoid.

Whole peptide-displayed phage particles are promising alternatives to antibodies in sensor development; however, greater control and functionalization of these particles are required. In this study, we aimed to identify and create highly sensitive and selective phage-based electrochemical biosensors for detecting ovomucoid, a known food allergen. Phage display was performed using two different phage libraries (cyclic and linear form of peptides), which displayed affinity peptides capable of binding specifically to ovomucoid.

Ultrasensitive and Selective Field-Effect Transistor-Based Biosensor Created by Rings of MoS Nanopores.

The ubiquitous field-effect transistor (FET) is widely used in modern digital integrated circuits, computers, communications, sensors, and other applications. However, reliable biological FET (bio-FET) is not available in real life due to the rigorous requirement for highly sensitive and selective bio-FET fabrication, which remains a challenging task. Here, we report an ultrasensitive and selective bio-FET created by the nanorings of molybdenum disulfide (MoS) nanopores inspired by nuclear pore complexes.

Fabrication of junction-free Cu nanowire networks via Ru-catalyzed electroless deposition and their application to transparent conducting electrodes.

Over the past few years, metal nanowire networks have attracted attention as an alternative to transparent conducting oxide materials such as indium tin oxide for transparent conducting electrode applications. Recently, electrodeposition of metal on nanoscale template is widely used for formation of metal network. In the present work, junctionless Cu nanowire networks were simply fabricated on a substrate by forming a nanostructured Ru with 80 nm width as a seed layer, followed by direct electroless deposition of Cu.

3D Hierarchical Polyaniline-Metal Hybrid Nanopillars: Morphological Control and Its Antibacterial Application.

Effective and reliable antibacterial surfaces are in high demand in modern society. Although recent works have shown excellent antibacterial performance by combining unique hierarchical nanotopological structures with functional polymer coating, determining the antibacterial performance arising from morphological changes is necessary. In this work, three-dimensional (3D) hierarchical polyaniline-gold (PANI/Au) hybrid nanopillars were successfully fabricated via chemical polymerization (i.

Touchable 3D hierarchically structured polyaniline nanoweb for capture and detection of pathogenic bacteria.

A bacteria-capturing platform is a critical function of accurate, quantitative, and sensitive identification of bacterial pathogens for potential usage in the detection of foodborne diseases. Despite the development of various nanostructures and their surface chemical modification strategies, relative to the principal physical contact propagation of bacterial infections, mechanically robust and nanostructured platforms that are available to capture bacteria remain a significant problem. Here, a three-dimensional (3D) hierarchically structured polyaniline nanoweb film is developed for the efficient capture of bacterial pathogens by hand-touching.

Cointegration of single-transistor neurons and synapses by nanoscale CMOS fabrication for highly scalable neuromorphic hardware.

Cointegration of multistate single-transistor neurons and synapses was demonstrated for highly scalable neuromorphic hardware, using nanoscale complementary metal-oxide semiconductor (CMOS) fabrication. The neurons and synapses were integrated on the same plane with the same process because they have the same structure of a metal-oxide semiconductor field-effect transistor with different functions such as homotype. By virtue of 100% CMOS compatibility, it was also realized to cointegrate the neurons and synapses with additional CMOS circuits.

Silicon Oxide Etching Process of NF and FNO Plasmas with a Residual Gas Analyzer.

The use of NF is significantly increasing every year. However, NF is a greenhouse gas with a very high global warming potential. Therefore, the development of a material to replace NF is required.

Pushbutton-activated microfluidic dropenser for droplet digital PCR.

Here, we report a portable microfluidic device to generate and dispense droplets simply operated by pushbutton for droplet digital polymerase chain reaction (ddPCR), which is named pushbutton-activated microfluidic dropenser (droplet dispenser) (PAMD). After loading the PCR mixtures and the droplet generation oil to PAMD, digitized PCR mixtures are prepared in PCR tubes after the actuation of a pushbutton. Multiple droplet generation units are simultaneously operated by a single pushbutton, and the size of droplets is controllable by adjusting the geometry of the droplet generation channel.

Concurrent Vacancy and Adatom Defects of MoNbSe Alloy Nanosheets Enhance Electrochemical Performance of Hydrogen Evolution Reaction.

Earth-abundant transition metal dichalcogenide nanosheets have emerged as an excellent catalyst for electrochemical water splitting to generate H. Alloying the nanosheets with heteroatoms is a promising strategy to enhance their catalytic performance. Herein, we synthesized hexagonal (2H) phase MoNbSe nanosheets over the whole composition range using a solvothermal reaction.

Scalable Superior Chemical Sensing Performance of Stretchable Ionotronic Skin via a π-Hole Receptor Effect.

Skin-attachable gas sensors provide a next-generation wearable platform for real-time protection of human health by monitoring environmental and physiological chemicals. However, the creation of skin-like wearable gas sensors, possessing high sensitivity, selectivity, stability, and scalability (4S) simultaneously, has been a big challenge. Here, an ionotronic gas-sensing sticker (IGS) is demonstrated, implemented with free-standing polymer electrolyte (ionic thermoplastic polyurethane, i-TPU) as a sensing channel and inkjet-printed stretchable carbon nanotube electrodes, which enables the IGS to exhibit high sensitivity, selectivity, stability (against mechanical stress, humidity, and temperature), and scalable fabrication, simultaneously.

3D Hierarchical Nanotopography for On-Site Rapid Capture and Sensitive Detection of Infectious Microbial Pathogens.

Effective capture and rapid detection of pathogenic bacteria causing pandemic/epidemic diseases is an important task for global surveillance and prevention of human health threats. Here, we present an advanced approach for the on-site capture and detection of pathogenic bacteria through the combination of hierarchical nanostructures and a nuclease-responsive DNA probe. The specially designed hierarchical nanocilia and network structures on the pillar arrays, termed 3D bacterial capturing nanotopographical trap, exhibit excellent mechanical reliability and rapid (<30 s) and irreversible bacterial capturability.

Clustered Regularly Interspaced Short Palindromic Repeats-Mediated Surface-Enhanced Raman Scattering Assay for Multidrug-Resistant Bacteria.

Antimicrobial resistance and multidrug resistance are slower-moving pandemics than the fast-spreading coronavirus disease 2019; however, they have potential to cause a much greater threat to global health. Here, we report a clustered regularly interspaced short palindromic repeats (CRISPR)-mediated surface-enhanced Raman scattering (SERS) assay for multidrug-resistant (MDR) bacteria. This assay was developed a synergistic combination of the specific gene-recognition ability of the CRISPR system, superb sensitivity of SERS, and simple separation property of magnetic nanoparticles.

Tie2-mediated vascular remodeling by ferritin-based protein C nanoparticles confers antitumor and anti-metastatic activities.

Background: Conventional therapeutic approaches for tumor angiogenesis, which are primarily focused on the inhibition of active angiogenesis to starve cancerous cells, target the vascular endothelial growth factor signaling pathway. This aggravates hypoxia within the tumor core and ultimately leads to increased tumor proliferation and metastasis. To overcome this limitation, we developed nanoparticles with antiseptic activity that target tumor vascular abnormalities.

Adatom Doping of Transition Metals in ReSe Nanosheets for Enhanced Electrocatalytic Hydrogen Evolution Reaction.

Two-dimensional Re dichalcogenide nanostructures are promising electrocatalysts for the hydrogen evolution reaction (HER). Herein, we report the adatom doping of various transition metals (TM = Mn, Fe, Co, Ni, and Cu) in ReSe nanosheets synthesized using a solvothermal reaction. As the atomic number of TM increases from Mn to Cu, the adatoms on Re sites become more favored over the substitution.

Thermally assisted nanotransfer printing with sub-20-nm resolution and 8-inch wafer scalability.

Nanotransfer printing (nTP) has attracted considerable attention due to its good pattern resolution, process simplicity, and cost-effectiveness. However, the development of a large-area nTP process has been hampered by critical reliability issues related to the uniform replication and regular transfer printing of functional nanomaterials. Here, we present a very practical thermally assisted nanotransfer printing (T-nTP) process that can easily produce well-ordered nanostructures on an 8-inch wafer via the use of a heat-rolling press system that provides both uniform pressure and heat.

Phase Evolution of ReMoSe Alloy Nanosheets and Their Enhanced Catalytic Activity toward Hydrogen Evolution Reaction.

Two-dimensional ReSe has emerged as a promising electrocatalyst for the hydrogen evolution reaction (HER), but its catalytic activity needs to be further improved. Herein, we synthesized ReMoSe alloy nanosheets with the whole range of (0-100%) using a hydrothermal reaction. The phase evolved in the order of 1T″ (triclinic) → 1T' (monoclinic) → 2H (hexagonal) upon increasing .

Flexible and highly ordered nanopillar electrochemical sensor for sensitive insulin evaluation.

In line with growing interest in obesity management, there has been an increase in the amount of research focused on highly sensitive analysis systems for a small number of biomarers. In this paper, we introduce the highly ordered nanopillar electrode, featuring a high aspect ratio surface area that enables enhanced electron transfer. For fabrication of the flexible electrode, gold was evaporated by electronic beam lithography on polyurethane (PU), which has high flexibility.

Se-Rich MoSe Nanosheets and Their Superior Electrocatalytic Performance for Hydrogen Evolution Reaction.

Two-dimensional MoSe has emerged as a promising electrocatalyst for the hydrogen evolution reaction (HER), although its catalytic activity needs to be further improved. Herein, we report Se-rich MoSe nanosheets synthesized using a hydrothermal reaction, displaying much enhanced HER performance at the Se/Mo ratio of 2.3.