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1.
The pandemic of coronavirus disease 2019 (COVID-19) reflects the great significance of rapid and accurate detection of pathogens by new sensing technologies. Antibody based biosensors with high sensitivity comparable to golden standard polymerase chain reaction (PCR) and miniaturized device features allow the detection of pathogens in portable and flexible formats. Herein, flexible metal oxide electrolyte-gated field-effect transistors (EGFETs) are reported to serve as the biosensors for rapid and ultrasensitive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. The semiconducting layer of the EGFETs associates with hybrid material of PEI doped metal oxides that not only improves the transistor performance, but also regulates microstructure forming higher surface-to-volume ratio, which brings more antibodies immobilization, resulting in higher sensitive, and faster response for detecting SARS-CoV-2. Comprehensive studies of materials and interfacing engineering of the EGFETs not only build the strong foundation for the EGFET sensors to show excellent sensitivity with a limit of detection from 0.14 fg ml−1 for SARS-CoV-2 S1 proteins, and 0.09 copies µl−1 for SARS-CoV-2 viruses, but also offer good mechanical properties to enable thin, soft flexible sensing platforms. This work provides a new strategy from materials to devices as innovative schemes for virus/pathogens detection.  相似文献   

2.
The world-wide spreading of coronavirus disease (COVID-19) has greatly shaken human society, thus effective and fast-speed methods of non-daily-life-disturbance sterilization have become extremely significant. In this work, by fully benefitting from high-quality AlN template (with threading dislocation density as low as ≈6×108 cm−2) as well as outstanding deep ultraviolet (UVC-less than 280 nm) light-emitting diodes (LEDs) structure design and epitaxy optimization, high power UVC LEDs and ultra-high-power sterilization irradiation source are achieved. Moreover, for the first time, a result in which a fast and complete elimination of SARS-CoV-2 (the virus causes COVID-19) within only 1 s is achieved by the nearly whole industry-chain-covered product. These results advance the promising potential in UVC-LED disinfection particularly in the shadow of COVID-19.  相似文献   

3.
For epidemic prevention and control, molecular diagnostic techniques such as field-effect transistor (FET) biosensors is developed for rapid screening of infectious agents, including Mycobacterium tuberculosis, SARS-CoV-2, rhinovirus, and others. They obtain results within a few minutes but exhibit diminished sensitivity (<75%) in unprocessed biological samples due to insufficient recognition of low-abundance analytes. Here, an electro-enhanced strategy is developed for the precise detection of trace-level infectious agents by liquid-gate graphene field-effect transistors (LG-GFETs). The applied gate bias preconcentrates analytes electrostatically at the sensing interface, contributing to a 10-fold signal enhancement and a limit of detection down to 5 × 10−16 g mL−1 MPT64 protein in serum. Of 402 participants, sensitivity in tuberculosis, COVID-19 and human rhinovirus assays reached 97.3% (181 of 186), and specificity is 98.6% (213 of 216) with a response time of <60 s. This study solves a long-standing dilemma that response speed and result accuracy of molecular diagnostics undergo trade-offs in unprocessed biological samples, holding unique promise in high-quality and population-wide screening of infectious diseases.  相似文献   

4.
Non-contact human-machine interaction is the future trend for wearable technologies. This demand is recently highlighted by the pandemic of coronavirus disease (COVID-19). Herein, an anti-fatigue and highly conductive hydrogel thermocell with photo-thermal conversion ability for non-contact self-powering applications is designed. Double hydrogen-bonding enhanced supramolecular hydrogel is obtained with N-acryloyl glycinamide (NAGA) and diacrylate capped Pluronic F68 (F68-DA) via one-step photo-initiated polymerization. The supramolecular hydrogel can accommodate saturated electrolytes to fulfill the triple function of ionic crosslinking, heat-to-electricity conversion, and light response of thermocell. Eminently, the thermocell stands out by virtue of its high seebeck coefficient (-2.17 mV K−1) and extraordinary toughness (Fatigue threshold ≈ 3120 J m−2). The self-powering ability under the control of light heating is explored, and a model of a non-contact “light-remoted” sensor with self-powered and sensing integrated performance remote-controlled by light is constructed. It is believed that this study will pave the way for the non-contact energy supply of wearable devices.  相似文献   

5.
A low‐cost and easy‐to‐fabricate microchip remains a key challenge for the development of true point‐of‐care (POC) diagnostics. Cellulose paper and plastic are thin, light, flexible, and abundant raw materials, which make them excellent substrates for mass production of POC devices. Herein, a hybrid paper–plastic microchip (PPMC) is developed, which can be used for both single and multiplexed detection of different targets, providing flexibility in the design and fabrication of the microchip. The developed PPMC with printed electronics is evaluated for sensitive and reliable detection of a broad range of targets, such as liver and colon cancer protein biomarkers, intact Zika virus, and human papillomavirus nucleic acid amplicons. The presented approach allows a highly specific detection of the tested targets with detection limits as low as 102 ng mL?1 for protein biomarkers, 103 particle per milliliter for virus particles, and 102 copies per microliter for a target nucleic acid. This approach can potentially be considered for the development of inexpensive and stable POC microchip diagnostics and is suitable for the detection of a wide range of microbial infections and cancer biomarkers.  相似文献   

6.
Polymeric capsules with a thick shell made of biodegradable and biocompatible polymer and a liquid core of perfluorooctyl bromide (PFOB) were evaluated for stability as well as for ultrasound and magnetic resonance imaging (MRI) contrast enhancement. The method of preparation allows the mean capsule diameter to be regulated between 70 nm and 25 µm and the capsule thickness‐to‐radius ratio from 0.25 to 0.54. Capsule diameter remains stable at 37 °C in phosphate buffer for at least 4 and 6 h for nanocapsules and microcapsules, respectively. The in vitro ultrasound signal‐to‐noise ratio (SNR) was measured from 40 to 60 MHz for 6 µm and 150 nm capsules: the SNR increases with capsule concentration up to 20–25 mg mL−1, and then reaches a plateau that depends on capsule diameter (13.5 ± 1.5 dB for 6 µm and 6 ± 2 dB for the 150 nm capsules). The ultrasound SNR is stable for up to 20 min for microcapsules and for several hours for nanocapsules. For nanocapsules, the thinner the shell, the larger the SNR and the more compressible the capsules. Nanocapsule suspensions imaged in vitro with a commercial ultrasound imaging system (normal and tissue harmonic imaging modes, 7–14 MHz probe) were detected down to concentrations of 12.5 mg mL−1. Injections of nanocapsules (200 µg ml−1) in mice in vivo reveal that the initial bolus passage presents significant ultrasound enhancement of the blood pool during hepatic imaging (7–14 MHz probe, tissue harmonic imaging mode). 19F‐MRI images were obtained in vitro at 9.4T using spin‐echo and gradient echo sequences and allow detecting nanocapsules in suspension (50 mg mL−1). In conclusion, these results show initial feasibility for development of these capsules toward a dual‐modality contrast agent.  相似文献   

7.
Heteroatom-incorporated graphene represents a prominent family of materials utilized as active electrodes for multimodal sensing and energy storage applications. Herein, a novel polyaziridine-encapsulated phosphorene (PEP)-incorporated flexible 3D porous graphene (3DPG) electrode is developed using facile, cost-effective laser writing, and drop-casting techniques. Owing to the excellent electrochemical characteristics and surface functionality of the highly stable PEP, the fabricated PEP/3DPG is evaluated as a potential electrode for immunosensing, electrocardiogram (ECG) recording, and microsupercapacitors (MSCs). Under optimized conditions, the produced PEP/3DPG-based carcinoembryonic immunosensor exhibits linear ranges of 0.1–700 pg mL−1 and 1–100 ng mL−1 with a detection limit of 0.34 pg mL−1 and high selectivity. The finger touch-based ECG sensor demonstrates a relatively low and stable impedance at the skin-electrode interface; therefore, the signal-to-noise ratio of the ECG signal received from the fabricated sensor (13.5 dB) is comparable to that of conventional Ag/AgCl electrodes (13.9 dB). Besides, the highest areal capacitance of the prepared MSC reached a magnitude of 16.94 mF cm−2, which is six times higher than that of a non-doped 3DPG-based MSC. These results demonstrate the effectiveness of the described fabrication procedure and the high utilization potential of the encapsulated phosphorene-doped 3D graphene in multimodal applications.  相似文献   

8.
In medical imaging procedures for the detection of coronavirus, apart from medical tests, approval of diagnosis has special significance. Imaging procedures are also useful for detecting the damage caused by COVID-19. Chest X-ray imaging is frequently used to diagnose COVID-19 and different pneumonias. This paper presents a task-specific framework to detect coronavirus in X-ray images. Binary classification of three different labels (healthy, bacterial pneumonia, and COVID-19) was performed on two differentiated data sets in which corona is stated as positive. First-order statistics, gray level co-occurrence matrix, gray level run length matrix, and gray level size zone matrix were analyzed to form fifteen sub-data sets and to ascertain the necessary radiomics. Two normalization methods are compared to make the data meaningful. Furthermore, five feature ranking approaches (Bhattacharyya, entropy, Roc, t-test, and Wilcoxon) are mentioned to provide necessary information to a state-of-the-art classifier based on Gauss-map-based chaotic particle swarm optimization and neural networks. The proposed framework was designed according to the analyses about radiomics, normalization approaches, and filter-based feature ranking methods. In experiments, seven metrics were evaluated to objectively determine the results: accuracy, area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, g-mean, precision, and f-measure. The proposed framework showed promising scores on two X-ray-based data sets, especially with the accuracy and area under the ROC curve rates exceeding 99% for the classification of coronavirus vs. others.  相似文献   

9.
Graphene field-effect transistors (G-FETs) have attracted widespread attention in disease diagnosis, benefiting from these advantages of high sensitivity, label-free, easy integration, and direct detection of nucleic acids (NAs) in liquid environments. However, the problem of nonspecific signals in G-FETs is not fundamentally solved due to a lack of systematic theoretical research to support the development of effective solutions. Thus, researchers have to rely on speculative mechanisms to minimize nonspecific signals in experiments as much as possible. Herein, the nonspecific signal mechanism caused by eight types of ππ interaction paths mediated by aromatic rings is theoretically determined. Based on theoretical simulation results, the feasibility of blocking nonspecific signal paths through Nafion functionalization methods is experimentally verified. Experiments confirm that Nafion-modified G-FETs (NMG-FETs) have excellent performance in avoiding nonspecific signals compared to traditional G-FETs. Furthermore, the NMG-FET achieves ultra-sensitive detection of Down syndrome–related DNA down to 1 aM and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA down to 5 aM, and shows good specificity in base recognition. This study is expected to promote the theoretical advancement of the nonspecific signal mechanism in G-FET NA detection and offer a practical strategy for improving signal purity and accuracy.  相似文献   

10.
A large number of deaths have been caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide, turning it into a serious and momentous threat to public health. This study tends to contribute to the development of effective treatment strategies through a computational approach, investigating the mechanisms in relation to the binding and subsequent inhibition of SARS-CoV-2 ribonucleic acid (RNA)-dependent RNA polymerase (RdRp). Molecular docking was performed to screen six naturally occurring molecules with antineoplastic properties (Ellipticine, Ecteinascidin, Homoharringtonine, Dolastatin 10, Halichondrin, and Plicamycin). Absorption, distribution, metabolism, and excretion (ADME) investigation was also conducted to analyze the drug-like properties of these compounds. The docked results have clearly shown binding of ligands to the SARS-CoV-2 RdRp protein. Interestingly, all ligands were found to obey Lipinski’s rule of five. These results provide a basis for repurposing and using molecules, derived from plants and animals, as a potential treatment for the coronavirus disease 2019 (COVID-19) infection as they could be effective therapeutics for the same.  相似文献   

11.
A novel strategy is reported for the fabrication of poly(diallyldimethylammonium chloride) (PDDA)‐protected graphene–CdSe (P‐GR‐CdSe) composites. An advanced electrogenerated chemiluminescence (ECL) immunosensor is proposed for the sensitive detection of human IgG (HIgG) by using the as‐prepared P‐GR‐CdSe composites. The P‐GR‐CdSe composite film shows high ECL intensity, good electronic conductivity, fast response, and satisfactory stability, all of which holds great promise for the fabrication of ECL biosensors with improved sensitivity. After two successive steps of amplification via the conjugation of PDDA and gold nanoparticles (GNPs) in the film, high ECL intensity is observed. The ECL immunosensor has an extremely sensitive response to HIgG in a linear range of 0.02–2000 pg mL?1 with a detection limit of 0.005 pg mL?1. The proposed sensor exhibits high specificity, good reproducibility, and long‐term stability, and may become a promising technique for protein detection.  相似文献   

12.
Developing selective and coherent polymorphic crystals at the nanoscale offers a novel strategy for designing integrated architectures for photonic and optoelectronic applications such as metasurfaces, optical gratings, photodetectors, and image sensors. Here, a direct optical writing approach is demonstrated to deterministically create polymorphic 2D materials by locally inducing metallic 1T′-MoTe2 on the semiconducting 2H-MoTe2 host layer. In the polymorphic-engineered MoTe2, 2H- and 1T′- crystalline phases exhibit strong optical contrast from near-infrared to telecom-band ranges (1–1.5 µm), due to the change in the band structure and increase in surface roughness. Sevenfold enhancement of third harmonic generation intensity is realized with conversion efficiency (susceptibility) of ≈1.7 × 10−7 (1.1 × 10−19 m2 V−2) and ≈1.7 × 10−8 (0.3 × 10−19 m2 V−2) for 1T′ and 2H-MoTe2, respectively at telecom-band ultrafast pump laser. Lastly, based on polymorphic engineering on MoTe2, a Schottky photodiode with a high photoresponsivity of 90 AW−1 is demonstrated. This study proposes facile polymorphic engineered structures that will greatly benefit realizing integrated photonics and optoelectronic circuits.  相似文献   

13.
Scintillators for radiation detection are of great significance in medical imaging, security, and nondestructive inspection. The current challenge for scintillators is to simultaneously achieve high scintillation light yield, fast radioluminescence, simple film fabrication, large X-ray attenuation efficiency as well as stable and nontoxic compositions; no previous scintillators fulfill all the above requirements. Here, metal halide Rb2AgBr3, possessing defect-bound excitonic radioluminescence, is shown as efficient and fast scintillators. This nontoxic and stable scintillator emits from excitons bound to neutral bromine vacancies, enjoying an efficient and spin-allowed fast emission with minimized self-absorption. Rb2AgBr3 thus has a high light yield (25 600 photons MeV−1), fast scintillation decay time (5.31 ns), and a record value of light yield versus decay time (4821 photons MeV−1 ns−1). The close-space sublimation method is developed for fast and scalable fabrication of oriented Rb2AgBr3 films. The scintillator film is further integrated with commercial flat-panel imagers, and the spatial resolution reaches 10.2 line pairs per millimeter at the modulation transfer function of 0.2, doubling the resolution of conventional CsI:Tl flat-panel detectors. The dynamic X-ray imaging and its use to real-time monitoring of bone movement without ghosting effect is also demonstrated.  相似文献   

14.
A novel nonenzymatic immunosensor for sensitive detection of Microcystin‐LR (MC‐LR) is constructed using a graphene platform combined with mesoporous PtRu alloy as a label for signal amplification. Primary antibody‐Microcystin‐LR (Ab1) is immobilized onto the surface of a graphene sheet (GS) through an amidation reaction between the carboxylic acid groups attached to the GS and the available amine groups of Ab1. Mesoporous PtRu alloy, prepared by corrosion PtRuAl alloys, is employed as a label to immobilize secondary antibody (Ab2). The resulting nanoparticles, PtRu‐Ab2, are used as labels for the immunosensor to detect MC‐LR. Under optimal conditions, the immunosensor exhibits a wide linear response to MC‐LR that ranges from 0.01 to 28 ng·mL?1, with a low detection limit of 9.63 pg·mL?1 MC‐LR. The proposed immunsensor shows good reproducibility, selectivity, and stability. The assayed results of polluted water with the sandwich‐type sensor are acceptable. Importantly, this methodology may provide a promising ultrasensitive assay strategy for other environmental pollutants.  相似文献   

15.
Excessive self-DNAs recognized by intracellular DNA sensors can initiate innate immunity to express disordered TNF-α or type I IFN resulting in several autoimmune diseases. Cationic polymers have been profoundly proved to alleviate the inflammatory symptoms by removing the debris of cell-free DNA (cfDNA). However, clinical applications of cationic materials have been impeded by concerns of their toxicity and the fate of cfDNA in polymer-cfDNA complex. Herein, it is showed that PEGylated polyimidazoles as a biomimetic DNase potently alleviate pathologic symptoms of self-DNA-associated rheumatoid arthritis (RA) rats and Trex1 (DNase III) deficient Aicardi-Goutiéres syndrome (AGS) mice. The mechanism studies demonstrate that the polyimidazole efficiently attacks the phosphodiester linkages of NAs and cleavages them into small pieces. As imidazole unit is a much weaker organic base that occurs in natural proteins, the polyimidazoles are less toxic to cells and tissues, as manifested by the IC50 values larger than 1000 µg mL−1. This work suggests that synthetic tailored DNase can be a new and safe therapeutic agent to treat chronic autoimmune and refractory inflammatory diseases by degradation of excessive nucleic acids.  相似文献   

16.
Transmission of pathogens via respiratory droplets can spread infections such as COVID-19. Wearing a mask hinders the spread of COVID-19 infection and has become mandatory in some cases. Although most masks are affordable and disposable, continual daily replacement is required due to their performance deterioration caused by washing and contamination. Hence, a urethane-reactive coating material comprising perfluoro-tert-butanol-hexamethylene diisocyanate is developed with highly hydrophobic and oleophobic properties to functionalize a polyurethane-coated fabric to bestow high breathability, durability, reusability, and protection ability. Its functions are maintained after scratch and wash testing, and its air permeability and water vapor transmittance rate (necessary for respiration) are unaffected. Its filtration efficiency of water droplets containing 100 nm polystyrene particles (similar in size to SARS-CoV-2) is increased due to its highly hydrophobic properties. In addition, it inhibits the adsorption of bovine serum albumin, the spike protein of COVID-19, and Staphylococcus aureus and Pseudomonas aeruginosa.  相似文献   

17.
Cytotoxic T-lymphocytes (CTLs) are central for eliciting protective immunity against malignancies and infectious diseases. Here, for the first time, partially oxidized acetalated dextran nanoparticles (Ox-AcDEX NPs) with an average diameter of 100 nm are fabricated as a general platform for vaccine delivery. To develop effective anticancer vaccines, Ox-AcDEX NPs are conjugated with a representative CTL peptide epitope (CTLp) from human mucin-1 (MUC1) with the sequence of TSAPDTRPAP (referred to as Mp1) and an immune-enhancing adjuvant R837 (referred to as R) via imine bond formation affording AcDEX-(imine)-Mp1-R NPs. Administration of AcDEX-(imine)-Mp1-R NPs results in robust and long-lasting anti-MUC1 CTL immune responses, which provides mice with superior protection from the tumor. To verify its universality, this nanoplatform is also exploited to deliver epitopes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to prevent coronavirus disease 2019 (COVID-19). By conjugating Ox-AcDEX NPs with the potential CTL epitope of SARS-CoV-2 (referred to as Sp) and R837, AcDEX-(imine)-Sp-R NPs are fabricated for anti-SARS-CoV-2 vaccine candidates. Several epitopes potentially contributing to the induction of potent and protective anti-SARS-CoV-2 CTL responses are examined and discussed. Collectively, these findings shed light on the universal use of Ox-AcDEX NPs to deliver both tumor-associated and virus-associated epitopes.  相似文献   

18.
The emergence of infectious diseases that are quickly spreading, like the coronavirus (COVID-19), necessitates the development of efficient biosensors that can quickly detect and identify pathogens. It is essential to create sensitive virus detection methods in order to stop a virus from spreading throughout the world. It is determined that field-effect transistors (FETs) made of nanomaterials are potential candidates for rapid virus identification due to how easily the electronic transport characteristics of such an atomically thin nanomaterial can be affected by perturbations. Various FETs in this review article are investigated that are based on nanoparticles, carbon nanotubes (CNT), graphene, graphene-oxide, and semiconducting transition metal dichalcogenides (TMDs) WSe2 in order to show that they are promising biosensors in regards to quickly and precisely detect COVID-19. The conjugation of nanomaterials with proteins enables the direct delivery of antiviral agents to the host cells. This method also minimizes the off-target effects and enables the targeted interactions. This mechanism has produced encouraging results in regards to sensing or treating COVID-19. The high surface area and extremely small size of nanomaterials make them crucial in regards to the development of new detection methods. The point-of-care test method of detection is quick, simple, and user-friendly, and it only requires a small amount of a patient's blood. It does not require a laboratory or trained professionals. This overview of the current research that is conducted on nanomaterials will prove to be useful in the process of formulating strategies for the diagnosis, treatment, and vaccination of viruses in opinion. Finally, the conclusion of this review provides a summary of the current challenges and the future prospects.  相似文献   

19.
Enzymatic DNA amplification‐based approaches involving intercalating DNA‐binding fluorescent dyes and expensive optical detectors are the gold standard for nucleic acid detection. As components of a simplified and miniaturized system, conventional silicon‐based ion sensitive field effect transistors (ISFETs) that measure a decrease in pH due to the generation of pyrophosphates during DNA amplification have been previously reported. In this article, Bst polymerase in a loop‐mediated isothermal amplification (LAMP) reaction combined with target‐specific primers and crumpled graphene field effect transistors (gFETs) to electrically detect amplification by sensing the reduction in primers is used. Graphene is known to adsorb single‐stranded DNA due to noncovalent π–π bonds, but not double‐stranded DNA. This approach does not require any surface functionalization and allows the detection of primer concentrations at the endpoint of reactions. As recently demonstrated, the crumpled gFET over the conventional flat gFET sensors due to their superior sensitivity is chosen. The endpoint of amplification reaction with starting concentrations down to 8 × 10?21 m in 90 min including the time of amplification and detection is detected. With its high sensitivity and small footprint, this platform will help bring complex lab‐based diagnostic and genotyping amplification assays to the point‐of‐care.  相似文献   

20.
This paper gives a brief overview of silicon-based microfluidic platforms developed over the years by our group for the extraction, amplification, and detection of nucleic acids. Extraction of both genomic and viral nucleic acids from whole blood has been demonstrated on Si-based microfluidics. Rapid amplification has been achieved by polymerase chain reaction in Si-based thermal reactors (micro-PCR). Detection has been realized by a chip-to-chip integration of the micro-PCR and micro capillary electrophoresis (micro-CE).  相似文献   

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