Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.419
Filtrar
1.
Small ; : e2403965, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38994696

RESUMEN

Nanotube and nanowire transistors hold great promises for future electronic and optoelectronic devices owing to their downscaling possibilities. In this work, a single multi-walled tungsten disulfide (WS2) nanotube is utilized as the channel of a back-gated field-effect transistor. The device exhibits a p-type behavior in ambient conditions, with a hole mobility µp ≈  1.4 cm2V-1s-1 and a subthreshold swing SS ≈ 10 V dec-1. Current-voltage characterization at different temperatures reveals that the device presents two slightly different asymmetric Schottky barriers at drain and source contacts. Self-powered photoconduction driven by the photovoltaic effect is demonstrated, and a photoresponsivity R ≈ 10 mAW-1 at 2 V drain bias and room temperature. Moreover, the transistor is tested for data storage applications. A two-state memory is reported, where positive and negative gate pulses drive the switching between two different current states, separated by a window of 130%. Finally, gate and light pulses are combined to demonstrate an optoelectronic memory with four well-separated states. The results herein presented are promising for data storage, Boolean logic, and neural network applications.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38995218

RESUMEN

Two-dimensional (2D) van der Waals heterostructures combine the distinct properties of individual 2D materials, resulting in metamaterials, ideal for emergent electronic, optoelectronic, and spintronic phenomena. A significant challenge in harnessing these properties for future hybrid circuits is their large-scale realization and integration into graphene interconnects. In this work, we demonstrate the direct growth of molybdenum disulfide (MoS2) crystals on patterned graphene channels. By enhancing control over vapor transport through a confined space chemical vapor deposition growth technique, we achieve the preferential deposition of monolayer MoS2 crystals on monolayer graphene. Atomic resolution scanning transmission electron microscopy reveals the high structural integrity of the heterostructures. Through in-depth spectroscopic characterization, we unveil charge transfer in Graphene/MoS2, with MoS2 introducing p-type doping to graphene, as confirmed by our electrical measurements. Photoconductivity characterization shows that photoactive regions can be locally created in graphene channels covered by MoS2 layers. Time-resolved ultrafast transient absorption (TA) spectroscopy reveals accelerated charge decay kinetics in Graphene/MoS2 heterostructures compared to standalone MoS2 and upconversion for below band gap excitation conditions. Our proof-of-concept results pave the way for the direct growth of van der Waals heterostructure circuits with significant implications for ultrafast photoactive nanoelectronics and optospintronic applications.

3.
Nanotechnology ; 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39019046

RESUMEN

This study examines the memory and read delay characteristics of quasi-nonvolatile memory (QNVM) devices operating in a positive feedback mechanism through technology computer-aided design simulation. The QNVM devices exhibit a rapid operation speed of 5 ns, a significant sensing margin of approximately 8.0 µA, and a retention time of around 1 s without any external bias. These devices showcase an exceptionally brief read delay of 0.12 ns. The energy band diagrams during the memory operation are analysed to clarify the factors influencing the read delay. The write and standby conditions modulate the potential barrier height during the standby operation, thereby affecting the read delay. Moreover, the shorter rising time causes the reduction of the read delay. This study demonstrates that the QNVM device has the potential to resolve energy consumption and speed issues in nonvolatile memory devices.

4.
J Nanobiotechnology ; 22(1): 414, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39010059

RESUMEN

Staphylococcus aureus (SA) poses a serious risk to human and animal health, necessitating a low-cost and high-performance analytical platform for point-of-care diagnostics. Cellulose paper-based field-effect transistors (FETs) with RNA-cleaving DNAzymes (RCDs) can fulfill the low-cost requirements, however, its high hydrophilicity and lipophilicity hinder biochemical modification and result in low sensitivity, poor mechanical stability and poor fouling performance. Herein, we proposed a controllable self-cleaning FET to simplify biochemical modification and improve mechanical stability and antifouling performance. Then, we constructed an RCD-based DNA nanotree to significantly enhance the sensitivity for SA detection. For controllable self-cleaning FET, 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane based-polymeric nanoparticles were synthesized to decorate cellulose paper and whole carbon nanofilm wires. O2 plasma was applied to regulate to reduce fluorocarbon chain density, and then control the hydrophobic-oleophobic property in sensitive areas. Because negatively charged DNA affected the sensitivity of semiconducting FETs, three Y-shaped branches with low-cost were designed and applied to synthesize an RCD-based DNA-Nanotree based on similar DNA-origami technology, which further improved the sensitivity. The trunk of DNA-Nanotree was composed of RCD, and the canopy was self-assembled using multiple Y-shaped branches. The controllable self-cleaning FET biosensor was applied for SA detection without cultivation, which had a wide linear range from 1 to 105 CFU/mL and could detect a low value of 1 CFU/mL.


Asunto(s)
Técnicas Biosensibles , ADN Catalítico , Staphylococcus aureus , ADN Catalítico/química , ADN Catalítico/metabolismo , Técnicas Biosensibles/métodos , Transistores Electrónicos , ARN/metabolismo , Límite de Detección , Celulosa/química , Papel , Nanopartículas/química , Humanos
5.
ACS Appl Mater Interfaces ; 16(28): 36804-36810, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38970471

RESUMEN

Osteoarthritis (OA), a prevalent degenerative joint disease, significantly affects the well-being of afflicted individuals and compromises the standard functionality of human joints. The emerging biomarker, Cartilage acidic protein 1 (CRTAC1), intricately associates with OA initiation and serves as a prognostic indicator for the trajectory toward joint replacement. However, existing diagnostic methods for CRTAC1 are hampered by the limited abundance, thus restricting the precision and specificity. Herein, a novel approach utilizing a single-walled carbon nanotube field-effect transistor (SWCNTs FET) biosensor is reported for the direct label-free detection of CRTAC1. High-purity semiconducting carbon nanotube films, functionalized with antibodies of CRTAC1, provide excellent electrical and sensing properties. The SWCNTs FET biosensor exhibits high sensitivity, notable reproducibility, and a wide linear detection range (1 fg/mL to 100 ng/mL) for CRTAC1 with a theoretical limit of detection (LOD) of 0.2 fg/mL. Moreover, the SWCNTs FET biosensor is capable of directly detecting human serum samples, showing excellent sensing performance in differentiating clinical samples from OA patients and healthy populations. Comparative analysis with traditional enzyme-linked immunosorbent assay (ELISA) reveals that the proposed biosensor demonstrates faster detection speeds, higher sensitivity/accuracy, and lower errors, indicating high potential for the early OA diagnosis. Furthermore, the SWCNTs FET biosensor has good scalability for the combined diagnosis and measurement of multiple disease markers, thereby significantly expanding the application of SWCNTs FETs in biosensing and clinical diagnostics.


Asunto(s)
Técnicas Biosensibles , Nanotubos de Carbono , Osteoartritis , Transistores Electrónicos , Nanotubos de Carbono/química , Técnicas Biosensibles/instrumentación , Humanos , Osteoartritis/diagnóstico , Osteoartritis/sangre , Límite de Detección , Biomarcadores/sangre , Biomarcadores/análisis
6.
ACS Appl Mater Interfaces ; 16(28): 36577-36585, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38972068

RESUMEN

Tin oxide is a promising channel material, offering the advantages of being low-cost and environmentally friendly and having a wide band gap. However, despite the high electron mobility of SnO2 in bulk, the corresponding thin-film transistors (TFTs) generally exhibit moderate performance, hindering their widespread application. Herein, we proposed a codoping strategy to improve both the electrical property and the stability of SnO2 TFTs. A comparative analysis between doped and undoped SnO2 was conducted. It is observed that taking advantage of the difference in ionic radii between two dopants (indium and gallium) and the tin ions in the host lattice can effectively reduce impurity-induced strain. Additionally, we investigated the effect of codoping content on SnO2 TFTs. The optimal codoped SnO2 (TIGO) TFTs demonstrate high performance, featuring a field-effect mobility of 15.9 cm2/V·s, a threshold voltage of 0.2 V, a subthreshold swing of 0.5 V/decade, and an on-to-off current ratio of 2.2 × 107. Furthermore, the devices show high stability under both positive and negative bias stress conditions with a small threshold voltage shift of 1.8 and -1.2 V, respectively. Utilizing the TIGO TFTs, we successfully constructed a resistor-loaded unipolar inverter with a high gain of 10.76. This study highlights the potential of codoped SnO2 TFTs for advanced applications in electronic devices.

7.
Materials (Basel) ; 17(13)2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38998423

RESUMEN

Group-III nitrides have transformed solid-state lighting and are strategically positioned to revolutionize high-power and high-frequency electronics. To drive this development forward, a deep understanding of fundamental material properties, such as charge carrier behavior, is essential and can also unveil new and unforeseen applications. This underscores the necessity for novel characterization tools to study group-III nitride materials and devices. The optical Hall effect (OHE) emerges as a contactless method for exploring the transport and electronic properties of semiconductor materials, simultaneously offering insights into their dielectric function. This non-destructive technique employs spectroscopic ellipsometry at long wavelengths in the presence of a magnetic field and provides quantitative information on the charge carrier density, sign, mobility, and effective mass of individual layers in multilayer structures and bulk materials. In this paper, we explore the use of terahertz (THz) OHE to study the charge carrier properties in group-III nitride heterostructures and bulk material. Examples include graded AlGaN channel high-electron-mobility transistor (HEMT) structures for high-linearity devices, highlighting the different grading profiles and their impact on the two-dimensional electron gas (2DEG) properties. Next, we demonstrate the sensitivity of the THz OHE to distinguish the 2DEG anisotropic mobility parameters in N-polar GaN/AlGaN HEMTs and show that this anisotropy is induced by the step-like surface morphology. Finally, we present the temperature-dependent results on the charge carrier properties of 2DEG and bulk electrons in GaN with a focus on the effective mass parameter and review the effective mass parameters reported in the literature. These studies showcase the capabilities of the THz OHE for advancing the understanding and development of group-III materials and devices.

8.
Small ; : e2403118, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38990881

RESUMEN

Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDCs) are extensively employed as channel materials in advanced electronic devices. The electrical contacts between electrodes and 2D semiconductors play a crucial role in the development of high-performance transistors. While numerous strategies for electrode interface engineering have been proposed to enhance the performance of n-type 2D transistors, upgrading p-type ones in a similar manner remains a challenge. In this work, significant improvements in a p-type WSe2 transistor are demonstrated by utilizing metallic MoO2 nanosheets as the electrode contact, which are controllably fabricated through physical vapor deposition and subsequent annealing. The MoO2 nanosheets exhibit an exceptional electrical conductivity of 8.4 × 104 S m‒1 and a breakdown current density of 3.3 × 106 A cm‒2. The work function of MoO2 nanosheets is determined to be ≈5.1 eV, making them suitable for contacting p-type 2D semiconductors. Employing MoO2 nanosheets as the electrode contact in WSe2 transistors results in a notable increase in the field-effect mobility to 92.0 cm2 V‒1 s‒1, which is one order of magnitude higher than the counterpart devices with conventional electrodes. This study not only introduces an intriguing 2D metal oxide to improve the electrical contact in p-type 2D transistors, but also offers an effective approach to fabricating all-2D devices.

9.
Nano Lett ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38981026

RESUMEN

We develop a novel metal contact approach using an antimony (Sb)-platinum (Pt) bilayer to mitigate Fermi-level pinning in 2D transition metal dichalcogenide channels. This strategy allows for control over the transport polarity in monolayer WSe2 devices. By adjustment of the Sb interfacial layer thickness from 10 to 30 nm, the effective work function of the contact/WSe2 interface can be tuned from 4.42 eV (p-type) to 4.19 eV (n-type), enabling selectable n-/p-FET operation in enhancement mode. The shift in effective work function is linked to Sb-Se bond formation and an emerging n-doping effect. This work demonstrates high-performance n- and p-FETs with a single WSe2 channel through Sb-Pt contact modulation. After oxide encapsulation, the maximum current density at |VD| = 1 V reaches 170 µA/µm for p-FET and 165 µA/µm for n-FET. This approach shows promise for cost-effective CMOS transistor applications using a single channel material and metal contact scheme.

10.
Artículo en Inglés | MEDLINE | ID: mdl-38982664

RESUMEN

With the increasing demand for elastic electronics, as a crucial component, elastic semiconductors have been widely studied. However, there are some issues for the current preparation of elastic semiconductors, such as harsh reaction conditions, low atomic economic utilization, and complicated product separation and purification. Aldehyde-amine polycondensation is an important chemical reaction with the advantages of mild reaction conditions, high atomic-economic efficiency, and easy separation and purification. Herein, intrinsically elastic semiconductors are developed via aldehyde-amine polycondensation, including a semiconducting segment and an elastic segment. The resulting polymer containing 42.62 wt % soft segments exhibits excellent stretchability and mechanical reversibility, especially with a lower modulus. Interestingly, the carrier mobility displays up to 0.04 cm2·V-1·s-1, in the range of the fully conjugated reference polymer (0.1 cm2·V-1·s-1). In brief, this strategy provides important guiding principles for the development of intrinsically elastic polymer semiconductors.

11.
Angew Chem Int Ed Engl ; : e202407039, 2024 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-39034433

RESUMEN

Given the high degree of variability and complexity of cancer, precise monitoring and logical analysis of different nucleic acid markers are crucial for improving diagnostic precision and patient survival rates. However, existing molecular diagnostic methods normally suffer from high cost, cumbersome procedures, dependence on specialized equipment and the requirement of in-depth expertise in data analysis, failing to analyze multiple cancer-associated nucleic acid markers and provide immediate results in a point-of-care manner. Herein, we demonstrate a transistor-based DNA molecular computing (TDMC) platform that enables simultaneous detection and logical analysis of multiple microRNA (miRNA) markers on a single transistor. TDMC can perform not only basic logical operations such as "AND" and "OR", but also complex cascading computing, opening up new dimensions for multi-index logical analysis. Owing to the high efficiency, sensing and computations of multi-analytes can be operated on a transistor at a concentration as low as 2×10-16 M, reaching the lowest concentration for DNA molecular computing. Thus, TDMC achieves an accuracy of 98.4% in the diagnosis of hepatocellular carcinoma from 62 serum samples. As a convenient and accurate platform, TDMC holds promise for applications in "one-stop" personalized medicine.

12.
Adv Sci (Weinh) ; : e2404336, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39041932

RESUMEN

The burgeoning need for extensive data processing has sparked enthusiasm for the development of a novel optical logic gate platform. In this study, junction field-effect phototransistors based on molybdenum disulfide/Germanium (MoS2/Ge) heterojunctions are constructed as optical logic units. This device demonstrates a positive photoresponse that is attributed to the photoconductivity effect occurring upon irradiation with visible (Vis) light. Under the illumination of near-infrared (NIR) optics with wavelengths within the communication band, the device shows a negative photoresponse, which is associated with the interlayer Coulomb interactions. The current state of the device can be effectively modulated as different logical states by precisely tuning the wavelength and power density of the optical. Within a 3 × 3 MoS2/Ge phototransistor array, five essentially all-optical logic gates ("AND," "OR," "NAND," "NOT," and "NOR") can be achieved in every signal unit. Furthermore, three complex all-optical logical operations are demonstrated by integrating two MoS2/Ge phototransistors in series. Compared to electronic designs, these all-optical logic devices offer a significant reduction in transistor number, with savings of 50-94% when implementing the above-mentioned functions. These results present opportunities for the development of photonic chips with low power consumption, high fidelity, and large volumes.

13.
Chemistry ; : e202401080, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39039606

RESUMEN

Inspired by the previous machine-learning study that the number of hydrogen-bonding acceptor (NHBA) is important index for the hole mobility of organic semiconductors, seven dithienobenzothiazole (DBT) derivatives 1a-g (NHBA = 5) were designed and synthesized by one-step functionalization from a common precursor. X-ray single-crystal structural analyses confirmed that the molecular arrangements of 1b (the diethyl and ethylthienyl derivative) and 1c (the di(n-propyl) and n-propylthienyl derivative) in the crystal are classified into brickwork structures with multidirectional intermolecular charge-transfer integrals, as a result of incorporation of multiple hydrogen-bond acceptors. The solution-processed top-gate bottom-contact devices of 1b and 1c had hole mobilities of 0.16 and 0.029 cm2 V-1s-1, respectively.

14.
Talanta ; 278: 126498, 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38959668

RESUMEN

Lung cancer is the main cancer that endangers human life worldwide, with the highest mortality rate. The detection of lung tumor markers is of great significance for the early diagnosis and subsequent treatment of lung cancer. In this study, a vertical graphene field effect transistor (VGFET) immunosensor based on graphene/C60 heterojunction was created to offer quantitative detections for the lung tumor markers carcinoembryonic antigen (CEA), cytokeratin 19 fragment (Cyfra21-1), and neuron-specific enolase (NSE). The experimental results showed that the sensitive range for standard antigen is between 1 pg/ml to 100 ng/ml, with a limit of detection (LOD) of 5.6 amol/ml for CEA, 33.3 amol/ml for Cyfra 21-1 and 12.8 amol/ml for NSE (1 pg/ml for all). The detection accuracy for these tumor markers was compared with the clinically used method for clinical patients on serum samples. Results are highly consistent with clinically used immunoassay in its efficient diagnosis concentration range. Subsequently, the mesoporous silica nanospheres (MSNs) with an average size of 90 nm were surface modified with glutaraldehyde, and a second antibody was assembled on MSNs, which fixes nanospheres on the antigen and amplified the field effect. The LODs for three markers are 100 fg/ml (0.56 amol/ml for CEA) under optimal circumstances of detection. This result indicates that specific binding to MSNs enhances local field effects and can achieve higher sensing efficiency for tumor marker detection at extremely low concentrations, providing effective assistance for the early diagnosis of lung cancer.

15.
Heliyon ; 10(11): e32281, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38961912

RESUMEN

We report the fabrication of two terminal and three terminal gas sensor using Al-doped ZnO nanostructured-films and polymer electrolyte gate dielectric on glass substrate using vacuum free chemical method. The Al doped ZnO films are characterized by UV-vis Spectrometer, SEM, EDX and XRD. The characterization results have revealed the polycrystalline structure of both undoped and doped ZnO; with loosely packed, porous, and spherical granny nanostructure with mean grain size 20-10 nm and bandgap of the films is within the range of 3.12-3.16 eV. The conductivity of the ZnO film is tuned by Al concentration and the maximum value of conductivity was observed in 3 % Al doped ZnO films. Similarly, the best performance index of TFT such as current ON/OFF ratio, high transconductance and low threshold voltage was observed in 3 % Al doping concentration. The ordinary (two-terminal) sensor and three-terminal (FET) sensors' responses towards three different concentrations 50, 250, 500 ppm of ethanol and methanol vapors have been studied. The sensitivity of the film is modulated by Al concentration and higher value of sensitivity was achieved at 3 % Al doped ZnO films. The use of polymer electrolyte enhanced the sensitivity of the device which is more effective in methanol vapor. The Response-Recovery time of the sensor is significantly improved in three terminal devices than the two terminal devices.

16.
Heliyon ; 10(11): e32325, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38947435

RESUMEN

Linearity and intermodulation distortion are very crucial parameters for RFICs design. Therefore, in this work, a detailed comparative analysis on linearity and intermodulation distortion of single metal (SMG) and double metal (DMG) double gate junction less transistor (JLT) is done using TCAD silvaco suite. Furthermore, the effects of temperature fluctuation, gate length variation, and gate material engineering on the linearity performance of both devices are also studied. A few significant figures of merit, including Voltage Intercept Point 2 (VIP2), Voltage Intercept Point 3 (VIP3), Third Order Intercept Power (IIP3), 1 dB Compression Point (P1dB), Third Order Intermodulation Distortion (IMD3), and the transconductance derivative parameters First Order Transconductance (gm1), Second Order Transconductance (gm2), and Third Order Transconductance (gm3) are used to assess the device linearity and intermodulation distortion of SMG and DMG JLT's. The findings show that higher VIP2, VIP3, IIP3, 1-dB compression point and lower gm3, IMD3 values are obtained for the SMG JLT device when compared to its counterpart DMG JLT. SMG JLT, which assures strong linearity and low distortion.

17.
Small ; : e2403629, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38958098

RESUMEN

Natural organisms have evolved precise sensing systems relying on unique ion channels, which can efficiently perceive various physical/chemical stimuli based on ionic signal transmission in biological fluid environments. However, it is still a huge challenge to achieve extensive applications of the artificial counterparts as an efficient wet sensing platform due to the fluidity of the working medium. Herein, nanofluidic membranes with selective cation transport properties and solid-state organic electrochemical transistors (OECTs) with amplified signals are integrated together to mimic human gustatory sensation, achieving ionic gustatory reagent recognition and a portable configuration. Cu-HHTP nanofluidic membranes with selective cation transport through their uniform micropores are constructed first, followed by assembly with OECTs to form the designed nanofluidic membrane-assisted OECTs (nanofluidic OECTs). As a result, they can distinguish typically ionic gustatory reagents, and even ionic liquids (ILs), demonstrating enhanced gustatory perception performance under a wide concentration range (10-7-10-1 m) compared with those of conventional OECTs. The linear correlations between the response and the reagent concentration further indicate the promising potential for practical application as a next-generation sensing platform. It is suggested that nanofluidic membranes mediated intramembrane cation transport based on the steric hindrance effect, resulting in distinguishable and improved response to multiple ions.

18.
Adv Sci (Weinh) ; : e2401915, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38958519

RESUMEN

Resistive switching memories have garnered significant attention due to their high-density integration and rapid in-memory computing beyond von Neumann's architecture. However, significant challenges are posed in practical applications with respect to their manufacturing process complexity, a leakage current of high resistance state (HRS), and the sneak-path current problem that limits their scalability. Here, a mild-temperature thermal oxidation technique for the fabrication of low-power and ultra-steep memristor based on Ag/TiOx/SnOx/SnSe2/Au architecture is developed. Benefiting from a self-assembled oxidation layer and the formation/rupture of oxygen vacancy conductive filaments, the device exhibits an exceptional threshold switching behavior with high switch ratio exceeding 106, low threshold voltage of ≈1 V, long-term retention of >104 s, an ultra-small subthreshold swing of 2.5 mV decade-1 and high air-stability surpassing 4 months. By decreasing temperature, the device undergoes a transition from unipolar volatile to bipolar nonvolatile characteristics, elucidating the role of oxygen vacancies migration on the resistive switching process. Further, the 1T1R structure is established between a memristor and a 2H-MoTe2 transistor by the van der Waals (vdW) stacking approach, achieving the functionality of selector and multi-value memory with lower power consumption. This work provides a mild-thermal oxidation technology for the low-cost production of high-performance memristors toward future in-memory computing applications.

19.
Discov Nano ; 19(1): 108, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38954140

RESUMEN

Nanosheet transistors are poised to become the preferred choice for the next generation of smaller-sized devices in the future. To address the future demand for high-performance and low-power computing applications, this study proposes a nanosheet structure with a vertically stacked design, featuring a high ION/IOFF ratio. This Nanosheet design is combined with an induced tunnel field-effect transistor. By utilizing SiGe with a carrier mobility three times that of Si and employing a line tunneling mechanism, the research successfully achieves superior Band to Band characteristics, resulting in improved switching behavior and a lower Subthreshold Swing (SS). Comparative studies were conducted on three TFET types: Nanosheet PIN TFET, Nanosheet Schottky iTFET, and Fin iTFET. Results show that the Nanosheet PIN TFET has a higher ION/IOFF ratio but poorer SSavg values at 47.63 mV/dec compared to the others. However, with a SiGe Body thickness of 3 nm, both Nanosheet iTFET and Fin iTFET exhibit higher ION/IOFF ratios and superior SSavg values at 17.64 mV/dec. These findings suggest the potential of Nanosheet iTFET and Fin iTFET for low-power, lower thermal budgets, and fast-switching applications.

20.
Biosens Bioelectron ; 262: 116548, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-38986250

RESUMEN

An effective strategy for accurately detecting single nucleotide variants (SNVs) is of great significance for genetic research and diagnostics. However, strict amplification conditions, complex experimental instruments, and specialized personnel are required to obtain a satisfactory tradeoff between sensitivity and selectivity for SNV discrimination. In this study, we present a CRISPR-based transistor biosensor for the rapid and highly selective detection of SNVs in viral RNA. By introducing a synthetic mismatch in the crRNA, the CRISPR-Cas13a protein can be engineered to capture the target SNV RNA directly on the surface of the graphene channel. This process induces a fast electrical signal response in the transistor, obviating the need for amplification or reporter molecules. The biosensor exhibits a detection limit for target RNA as low as 5 copies in 100 µL, which is comparable to that of real-time quantitative polymerase chain reaction (PCR). Its operational range spans from 10 to 5 × 105 copy mL-1 in artificial saliva solution. This capability enables the biosensor to discriminate between wild-type and SNV RNA within 15 min. By introducing 10 µL of swab samples during clinical testing, the biosensor provides specific detection of respiratory viruses in 19 oropharyngeal specimens, including influenza A, influenza B, and variants of SARS-CoV-2. This study emphasizes the CRISPR-transistor technique as a highly accurate and sensitive approach for field-deployable nucleic acid screening or diagnostics.


Asunto(s)
Técnicas Biosensibles , Sistemas CRISPR-Cas , Polimorfismo de Nucleótido Simple , ARN Viral , Transistores Electrónicos , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Humanos , Sistemas CRISPR-Cas/genética , ARN Viral/genética , ARN Viral/aislamiento & purificación , ARN Viral/análisis , Polimorfismo de Nucleótido Simple/genética , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Disparidad de Par Base , Límite de Detección , COVID-19/virología , COVID-19/diagnóstico , Grafito/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA