Monolayer transition metal dichalcogenides are materials with an atomic structure complementary to graphene but diverse properties, including direct energy bandgaps, which makes them intriguing candidates for optoelectronic devices. Various approaches have been demonstrated the growth of molybdenum disulphide (MoS2) on insulating substrates, date, isolated crystalline flakes has at random locations only. Here we use patterned seeds source material grow MoS2 predetermined micrometre-scale...

Growth of transition metal dichalcogenide (TMD) monolayers is interest due to their unique electrical and optical properties. Films in the 2H 1T phases have been widely studied but some 1T′-TMDs are predicted be large-gap quantum spin Hall insulators, suitable for innovative transistor structures that can switched via a topological phase rather than conventional carrier depletion [Qian et al. Science 2014, 346, 1344−1347]. Here we detail reproducible method chemical vapor deposition...

Scalable production of all-electronic DNA biosensors with high sensitivity and selectivity is a critical enabling step for research applications associated detection hybridization. We have developed scalable very reproducible (> 90% yield) fabrication process label-free based upon graphene field effect transistors (GFETs) functionalized single-stranded probe DNA. The shift the GFET sensor Dirac point voltage varied systematically concentration target demonstrated broad analytical range limit...

All-electronic DNA biosensors based on graphene field-effect transistors (GFETs) offer the prospect of simple and cost-effective diagnostics. For GFET sensors complementary probe DNA, sensitivity is limited by binding affinity target oligonucleotide, in nM range for 20 mer targets. We report a ∼20 000× improvement through use engineered hairpin that allows recycling hybridization chain reaction. This enables detection 21 at sub-fM concentration provides superior specificity against...

Abstract Electronic DNA‐biosensor with a single nucleotide resolution capability is highly desirable for personalized medicine. However, existing DNA‐biosensors, especially polymorphism (SNP) detection systems, have poor sensitivity and specificity lack real‐time wireless data transmission. DNA‐tweezers graphene field effect transistor (FET) are used SNP transmitted wirelessly analysis. Picomolar of quantitative achieved by observing changes in Dirac point shift resistance change. The use...

We have developed a scalable fabrication process for the production of DNA biosensors based on gold nanoparticle-decorated graphene field effect transistors (AuNP-Gr-FETs), where monodisperse AuNPs are created through physical vapor deposition followed by thermal annealing. The FETs in four-probe configuration, using an optimized bilayer photolithography that yields chemically clean devices, as confirmed XPS and AFM, with high carrier mobility (3590 ± 710 cm2/V·s) low unintended doping...

We developed a high-yield synthesis of highly crystalline bilayer graphene (BLG) with two preferential stacking modes using Ni–Cu gradient alloy growth substrate. Previously reported approaches for BLG include flat substrates Cu or uniform alloys and "copper pocket" structures. Use has the advantage being scalable, but mechanism is either "surface limited" (for Cu) carbon precipitation Ni–Cu), which results in multicrystalline grains. For copper pockets, proceeds through back-diffusion...

Biosensors based on graphene field effect transistors (GFETs) decorated with antibody‐functionalized platinum nanoparticles (PtNPs) are developed for the quantitative detection of breast cancer biomarker HER3. High‐quality chemical vapor deposited is prepared and transferred over gold electrodes microfabricated an SiO 2 /Si wafer to yield array 52 GFET devices. The GFETs modified PtNPs obtain a hybrid nanostructure suitable attachment HER3‐specific, genetically engineered thiol‐containing...

This report describes the development of an aptamer for sensing azole antifungal drugs therapeutic drug monitoring. Modified Synthetic Evolution Ligands through Exponential Enrichment (SELEX) was used to discover a DNA recognizing class drugs. undergoes secondary structural change upon binding its target molecule as shown fluorescence anisotropy-based measurements. Experiments using circular dichroism spectroscopy, revealed unique double G-quadruplex structure that essential and specific...

Simpler and more rapid approaches for therapeutic drug-level monitoring are highly desirable to enable use at the point-of-care. We have developed an all-electronic approach detection of HIV drug tenofovir based on scalable fabrication arrays graphene field-effect transistors (GFETs) functionalized with a commercially available DNA aptamer. The shift in Dirac voltage GFETs varied systematically concentration deionized water, limit less than 1 ng/mL. Tests against set negative controls...

Graphene-based biosensors can be produced in a scalable manner at reasonable cost, and they show significant promise for sensitive detection of small molecules biomarkers such as proteins, single strand nucleic acids, drug targets. Here, we describe an approach that enables limit ~1 aM ssDNA target without amplification. We also sensor based on short (20mer) probe complementary to portion longer (100mer) provides enhanced sensitivity saturation signal level. Finally, graphene-based DNA...

Abstract All-electronic interrogation of biofluid flow velocity by electrical nanosensors incorporated in ultra-low-power or self-sustained systems offers the promise enabling multifarious emerging research and applications. However, existing nano-based sensing technologies remain lacking precision stability are typically only applicable to simple aqueous solutions liquid/gas dual-phase mixtures, making them unsuitable for monitoring low-flow (~micrometer/second) yet important...

Enhancing the detection limit in protein analysis is essential for a wide range of biomedical applications. In typical fluorescent assays, this constrained by capacity photon detector. Here, we develop an approach that significantly enhances threshold using microscale isoelectric focusing implemented directly at site on sensor chip. We demonstrate electrically generating localized pH environment within radius ∼60 μm, molecules can be concentrated and detected levels over four times lower...

Opioid neuropeptides play a significant role in pain perception, appetite regulation, sleep, memory, and learning. Advances understanding of opioid peptide physiology are held back by the lack methodologies for real-time quantification affinities kinetics neuropeptide–receptor interaction at levels typical endogenous secretion (<50 pM) biosolutions with physiological ionic strength. To address this challenge, we developed all-electronic opioid–neuropeptide biosensors based on graphene...

Real-time, all-electronic control of non-Newtonian fluid flow through a microscale channel is crucial for various applications in manufacturing and healthcare. However, existing methods lack the sensitivity required accurate measurement real-time responsiveness necessary effective adjustment. Here, we demonstrate an system that enables closed-loop, real-time, high-sensitivity waveforms (0.76 μl min−1) micro-sized outlet. Our approach combines contactless, cuff-like sensor with neural-network...

Liquid-based bio-applications of graphene require a quantitative understanding the graphene-liquid interface, with surface charge density adsorbed ions, interfacial transfer resistance, and noise being particular importance. We quantified these properties through measurements zero-bias Faradaic charge-transfer between electrodes aqueous solutions varying ionic strength using reproducible, low-noise, minimally perturbative measurement technique. The indicated that ions had negative...

Overcoming throughput challenges in current graphene defect healing processes, such as conventional thermal annealing, is crucial for realizing post-silicon device fabrication. Herein, a new time- and energy-efficient method reported, utilizing polymer-assisted rapid annealing (RTA). In this method, nitrogen-rich, polymeric "nanobandage" coated directly onto processed via RTA at 800 °C 15 s. During process, the polymer matrix cleanly degraded, while nitrogen released from nanobandage can...

Advances in techniques for monitoring pH complex fluids can have a significant impact on analytical and biomedical applications. This study develops flexible graphene microelectrodes (GEs) rapid (&lt;5 s), very‐low‐power (femtowatt) detection of the biofluids by measuring real‐time Faradaic charge transfer between GE solution at zero electrical bias. For an idealized sample phosphate buffer (PBS), current is varied monotonically systematically with pH, resolution ≈0.2 unit. The current–pH...

A water-soluble variant of the transmembrane domain human mu opioid receptor (wsMOR-TM) was previously characterized. This study explored whether full-length version engineered receptor, (wsMOR-FL), could be overexpressed in Escherichia coli and if it would retain water solubility, binding capability thermostability. wsMOR over-expressed purified E. BL21(DE3) cells (EMD/Novagen) as we reported for wsMOR-TM. Both native N C termini were added back to highly Six His-tag terminus purification...

The characterization of protein-nanoparticle assemblies in solution remains a challenge. We demonstrate technique based on graphene microelectrode for structural-functional analysis model systems composed nanoparticles enclosed open-pore and closed-pore ferritin molecules. method readily resolves the difference accessibility nanoparticle charge transfer offers prospect quantitative pore-mediated transport shed light spatial orientation protein subunits surface, faster with higher sensitivity...

Precise sensing of microfluidic flow is essential to advancing lab-on-a-chip development and the downstream medical applications. Contactless interrogation noninvasive, nonperturbative, fouling-free. However, known real non-contact technologies are limited quantifying bulk fluids. Here, we develop an electrical approach contactless quantification aqueous flow. We found that electric potential generated by ubiquitous contact electrification a with fluidic channel walls interrogatable using...

Accurate regulation of extracellular pH is crucial for controlling cell behaviors and functions. However, typical methods, which primarily rely on replacing culture media or using ionic diffusion, are slow, nondirectional, lack spatiotemporal resolution. Here, we develop a microfabricated device that regulates microenvironmental within specific localized zones with high precision (uncertainty <0.1 units) temporal The uses synchronization strategy coordinates two processes: pulsatile...