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1.
ACS Appl Mater Interfaces ; 14(1): 191-200, 2022 Jan 12.
Article in English | MEDLINE | ID: covidwho-1616941

ABSTRACT

At present, the most powerful new drugs for COVID-19 are antibody proteins. In addition, there are some star small molecule drugs. However, there are few studies on nanomaterials. Here, we study the intact graphene (IG), defective graphene (DG), and graphene oxide (GO) interacting with COVID-19 protein. We find that they show progressive inhibition of COVID-19 protein. By using molecular dynamics simulations, we study the interactions between SARS-CoV-2 3CL Mpro and graphene-related materials (GRMs): IG, DG, and GO. The results show that Mpro can be absorbed onto the surfaces of investigated materials. DG and GO interacted with Mpro more intensely, causing the decisive part of Mpro to become more flexible. Further analysis shows that compared to IG and GO, DG can inactivate Mpro and inhibit its expression effectively by destroying the active pocket of Mpro. Our work not only provides detailed and reliable theoretical guidance for the application of GRMs in treating with SARS-CoV-2 but also helps in developing new graphene-based anti-COVID-19 materials.


Subject(s)
Coronavirus 3C Proteases/chemistry , Graphite/chemistry , Molecular Dynamics Simulation , SARS-CoV-2/metabolism , Adsorption , Binding Sites , COVID-19/pathology , COVID-19/virology , Catalytic Domain , Coronavirus 3C Proteases/metabolism , Graphite/metabolism , Humans , Ligands , SARS-CoV-2/isolation & purification
2.
J Phys Chem B ; 126(1): 151-160, 2022 01 13.
Article in English | MEDLINE | ID: covidwho-1608949

ABSTRACT

A rapid and noninvasive way to monitor the spread of COVID-19 is the detection of SARS-CoV-2 biomarkers from exhaled breath. Heptanal was identified as a key biomarker which was significantly elevated in the breath of SARS-CoV-2 patients. In this study, the adsorption behaviors of heptanal on pristine and transition metal (Pd, Pt, and Ag) doped graphene were studied based on density functional theory. The results indicated that heptanal was weakly adsorbed on pristine graphene with an adsorption energy of -0.015 eV while it was strongly adsorbed on Pd-, Pt-, and Ag-doped graphene with adsorption energies of -0.404, - 0.356, and -0.755 eV, respectively. Also, the electronic properties of Pd-, Pt-, and Ag-doped graphene changed more dramatically after heptanal adsorption than pristine graphene. The recovery times were estimated to be 6.13 × 10-6, 9.57 × 10-7, and 4.83 s for Pd-, Pt-, and Ag-doped graphene, respectively, showing that Pd-, Pt-, and Ag-doped graphene are suitable as reversible sensors. Our results conclude that Pd-, Pt-, and Ag-doped graphene are potential candidates as gas sensors for heptanal detection, and Ag-doped graphene is the most promising one.


Subject(s)
COVID-19 , Graphite , Aldehydes , Biomarkers , Humans , SARS-CoV-2
3.
ACS Biomater Sci Eng ; 8(1): 54-81, 2022 01 10.
Article in English | MEDLINE | ID: covidwho-1593020

ABSTRACT

Viral diseases have long been among the biggest challenges for healthcare systems around the world. The recent Coronavirus Disease 2019 (COVID-19) pandemic is an example of how complicated the situation can get if we are not prepared to combat a viral outbreak in time, which brings up the need for quick and affordable biosensing platforms and vast knowledge of potential antiviral effects and drug/gene delivery opportunities. The same challenges have also existed for nonviral immunogenic disorders. Nanomedicine is considered a novel candidate for effectively overcoming these worldwide challenges. Among the versatile nanomaterials commonly used in biomedical applications, graphene has recently earned much attention thanks to its special and inspiring physicochemical properties, such as its large surface area, efficient thermal/electrical properties, carbon-based chemical purity with controllable biocompatibility, easy functionalization, capability of single-molecule detection, anticancer characteristics, 3D template feature in tissue engineering, and, in particular, antibacterial/antiviral activities. In this Review, the most important and challenging viruses of our era, such as human immunodeficiency virus, Ebola, SARS-CoV-2, norovirus, and hepatitis virus, and immunogenic disorders, such as asthma, Alzheimer's disease, and Parkinson's disease, in which graphene-based nanomaterials can effectively take part in the prevention, detection, treatment, medication, and health effect issues, have been covered and discussed.


Subject(s)
COVID-19 , Graphite , Nanostructures , Viruses , Humans , SARS-CoV-2
4.
Environ Sci Process Impacts ; 23(7): 923-946, 2021 Jul 21.
Article in English | MEDLINE | ID: covidwho-1559452

ABSTRACT

Globally, humanity is facing its most significant challenge in 100 years due to the novel coronavirus, SARS-CoV-2, which is responsible for COVID-19. Under the enormous pressure created by the pandemic, scientists are studying virus transmission mechanisms in order to develop effective mitigation strategies. However, no established methods have been developed to control the spread of this deadly virus. In addition, the ease in lockdown has escalated air pollution which may affect SARS-CoV-2 transmission through attachment to particulates. The present review summarizes the role of graphene nanomaterials, which show antimicrobial behavior and have antiviral efficacy, in reducing the spread of COVID-19. Graphene and its derivatives have excellent antimicrobial efficacy, providing both physical and chemical mechanisms of damage. Coupled with their lightness, optimal properties, and ease of functionalization, they are optimal nanomaterials for coating onto fabrics such as personal protection equipment, face masks and gloves to control the transmission of SARS-CoV-2 effectively. Biosensors using graphene can effectively detect the virus with high accuracy and sensitivity, providing rapid quantification. It is envisioned that the present work will boost the development of graphene-based highly sensitive, accurate and cost-effective diagnostic tools for efficiently monitoring and controlling the spread of COVID-19 and other air-borne viruses.


Subject(s)
Air Pollutants , COVID-19 , Graphite , Air Pollutants/analysis , Cities , Communicable Disease Control , Humans , India , Pandemics , SARS-CoV-2
5.
Biosens Bioelectron ; 199: 113866, 2022 Mar 01.
Article in English | MEDLINE | ID: covidwho-1560591

ABSTRACT

The outbreak of COVID-19 pandemics highlighted the need of sensitive, selective, and easy-to-handle biosensing devices. In the contemporary scenario, point-of-care devices for mass testing and infection mapping within a population have proven themselves as of primordial importance. Here, we introduce a graphene-based Electrical-Electrochemical Vertical Device (EEVD) point-of-care biosensor, strategically engineered for serologic COVID-19 diagnosis. EEVD uses serologic IgG quantifications on SARS-CoV-2 Receptor Binding Domain (RBD) bioconjugate immobilized onto device surface. EEVD combines graphene basal plane with high charge carrier mobility, high conductivity, low intrinsic resistance, and interfacial sensitivity to capacitance alterations. EEVD application was carried out in real human serum samples. Since EEVD is a miniaturized device, it requires just 40 µL of sample for a point-of-care COVID-19 infections detection. When compared to serologic assays such ELISA and other immunochromatographic methods, EEVD presents some advantages such as time of analyses (15 min), sample preparation, and a LOD of 1.0 pg mL-1. We glimpse that EEVD meets the principles of robustness and accuracy, desirable analytic parameters for assays destined to pandemics control strategies.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Antibodies, Viral , COVID-19 Testing , Humans , Point-of-Care Systems , SARS-CoV-2 , Sensitivity and Specificity , Serologic Tests
6.
Biosens Bioelectron ; 197: 113803, 2022 Feb 01.
Article in English | MEDLINE | ID: covidwho-1517063

ABSTRACT

We report the rapid detection of SARS-CoV-2 in infected patients (mid-turbinate swabs and exhaled breath aerosol samples) in concentrations as low as 60 copies/mL of the virus in seconds by electrical transduction of the SARS-CoV-2 S1 spike protein antigen via SARS-CoV-2 S1 spike protein antibodies immobilized on bilayer quasi-freestanding epitaxial graphene without gate or signal amplification. The sensor demonstrates the spike protein antigen detection in a concentration as low as 1 ag/mL. The heterostructure of the SARS-CoV-2 antibody/graphene-based sensor is developed through a simple and low-cost fabrication technique. Furthermore, sensors integrated into a portable testing unit distinguished B.1.1.7 variant positive samples from infected patients (mid-turbinate swabs and saliva samples, 4000-8000 copies/mL) with a response time of as fast as 0.6 s. The sensor is reusable, allowing for reimmobilization of the crosslinker and antibodies on the biosensor after desorption of biomarkers by NaCl solution or heat treatment above 40 °C.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Humans , SARS-CoV-2
7.
J Am Chem Soc ; 143(43): 17891-17909, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1483091

ABSTRACT

The emergence of multi-drug-resistant pathogens threatens the healthcare systems world-wide. Recent advances in phototherapy (PT) approaches mediated by photo-antimicrobials (PAMs) provide new opportunities for the current serious antibiotic resistance. During the PT treatment, reactive oxygen species or heat produced by PAMs would react with the cell membrane, consequently leaking cytoplasm components and effectively eradicating different pathogens like bacteria, fungi, viruses, and even parasites. This Perspective will concentrate on the development of different organic photo-antimicrobials (OPAMs) and their application as practical therapeutic agents into therapy for local infections, wound dressings, and removal of biofilms from medical devices. We also discuss how to design highly efficient OPAMs by modifying the chemical structure or conjugating with a targeting component. Moreover, this Perspective provides a discussion of the general challenges and direction for OPAMs and what further needs to be done. It is hoped that through this overview, OPAMs can prosper and will be more widely used for microbial infections in the future, especially at a time when the global COVID-19 epidemic is getting more serious.


Subject(s)
Anti-Infective Agents/chemistry , Drug Design , Phototherapy/methods , Animals , Anti-Infective Agents/pharmacology , Anti-Infective Agents/therapeutic use , Bacteria/drug effects , Biofilms/drug effects , Biofilms/radiation effects , Coloring Agents/chemistry , Coloring Agents/pharmacology , Equipment and Supplies/microbiology , Equipment and Supplies/virology , Escherichia coli/drug effects , Escherichia coli/physiology , Eye Diseases/drug therapy , Eye Diseases/pathology , Fungi/drug effects , Graphite/chemistry , Light , Nanoparticles/chemistry , Nanoparticles/toxicity , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Quantum Theory , Reactive Oxygen Species/metabolism , Viruses/drug effects
8.
J Am Chem Soc ; 143(41): 17004-17014, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1461966

ABSTRACT

Rapid screening of infected individuals from a large population is an effective means in epidemiology, especially to contain outbreaks such as COVID-19. The gold standard assays for COVID-19 diagnostics are mainly based on the reverse transcription polymerase chain reaction, which mismatches the requirements for wide-population screening due to time-consuming nucleic acid extraction and amplification procedures. Here, we report a direct nucleic acid assay by using a graphene field-effect transistor (g-FET) with Y-shaped DNA dual probes (Y-dual probes). The assay relies on Y-dual probes modified on g-FET simultaneously targeting ORF1ab and N genes of SARS-CoV-2 nucleic acid, enabling high a recognition ratio and a limit of detection (0.03 copy µL-1) 1-2 orders of magnitude lower than existing nucleic acid assays. The assay realizes the fastest nucleic acid testing (∼1 min) and achieves direct 5-in-1 pooled testing for the first time. Owing to its rapid, ultrasensitive, easily operated features as well as capability in pooled testing, it holds great promise as a comprehensive tool for population-wide screening of COVID-19 and other epidemics.


Subject(s)
DNA Probes , DNA, Viral/analysis , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics , COVID-19/diagnosis , COVID-19/virology , Graphite/chemistry , Humans , Limit of Detection
9.
Nano Lett ; 21(19): 7897-7904, 2021 10 13.
Article in English | MEDLINE | ID: covidwho-1440453

ABSTRACT

The fast spread of SARS-CoV-2 has severely threatened the public health. Establishing a sensitive method for SARS-CoV-2 detection is of great significance to contain the worldwide pandemic. Here, we develop a graphene field-effect transistor (g-FET) biosensor and realize ultrasensitive SARS-CoV-2 antibody detection with a limit of detection (LoD) down to 10-18 M (equivalent to 10-16 g mL-1) level. The g-FETs are modified with spike S1 proteins, and the SARS-CoV-2 antibody biorecognition events occur in the vicinity of the graphene surface, yielding an LoD of ∼150 antibodies in 100 µL full serum, which is the lowest LoD value of antibody detection. The diagnoses time is down to 2 min for detecting clinical serum samples. As such, the g-FETs leverage rapid and precise SARS-CoV-2 screening and also hold great promise in prevention and control of other epidemic outbreaks in the future.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Humans , Limit of Detection , SARS-CoV-2
10.
ACS Sens ; 6(9): 3468-3476, 2021 09 24.
Article in English | MEDLINE | ID: covidwho-1392782

ABSTRACT

This research reveals the promising functionalization of graphene oxide (GrO)-glazed double-interdigitated capacitive (DIDC) biosensing platform to detect severe acute respiratory syndrome coronavirus (SARS-CoV-2) spike (S1) proteins with enhanced selectivity and rapid response. The DIDC bioactive surface consisting of Pt/Ti featured SiO2 substrate was fabricated using GrO/EDC-NHS/anti-SARS-CoV-2 antibodies (Abs) which is having layer-by-layer interface self-assembly chemistry method. This electroactive immune-sensing platform exhibits reproducibility and sensitivity with reference to the S1 protein of SARS-CoV-2. The outcomes of analytical studies confirm that GrO provided a desired engineered surface for Abs immobilization and amplified capacitance to achieve a wide detection range (1.0 mg/mL to 1.0 fg/mL), low limit of detection (1 fg/mL) within 3 s of response time, good linearity (18.56 nF/g), and a high sensitivity of 1.0 fg/mL. Importantly, the unique biochip was selective against blood-borne antigens and standby for 10 days at 5 °C. Our developed DIDC-based SARS-CoV-2 biosensor is suitable for point-of-care (POC) diagnostic applications due to portability and scaling-up ability. In addition, this sensing platform can be modified for the early diagnosis of severe viral infections using real samples.


Subject(s)
COVID-19 , SARS-CoV-2 , Graphite , Humans , Reproducibility of Results , Silicon Dioxide , Spike Glycoprotein, Coronavirus
11.
ACS Appl Mater Interfaces ; 13(36): 43696-43707, 2021 Sep 15.
Article in English | MEDLINE | ID: covidwho-1392772

ABSTRACT

Graphene is a two-dimensional semiconducting material whose application for diagnostics has been a real game-changer in terms of sensitivity and response time, variables of paramount importance to stop the COVID-19 spreading. Nevertheless, strategies for the modification of docking recognition and antifouling elements to obtain covalent-like stability without the disruption of the graphene band structure are still needed. In this work, we conducted surface engineering of graphene through heterofunctional supramolecular-covalent scaffolds based on vinylsulfonated-polyamines (PA-VS). In these scaffolds, one side binds graphene through multivalent π-π interactions with pyrene groups, and the other side presents vinylsulfonated pending groups that can be used for covalent binding. The construction of PA-VS scaffolds was demonstrated by spectroscopic ellipsometry, Raman spectroscopy, and contact angle measurements. The covalent binding of -SH, -NH2, or -OH groups was confirmed, and it evidenced great chemical versatility. After field-effect studies, we found that the PA-VS-based scaffolds do not disrupt the semiconducting properties of graphene. Moreover, the scaffolds were covalently modified with poly(ethylene glycol) (PEG), which improved the resistance to nonspecific proteins by almost 7-fold compared to the widely used PEG-monopyrene approach. The attachment of recognition elements to PA-VS was optimized for concanavalin A (ConA), a model lectin with a high affinity to glycans. Lastly, the platform was implemented for the rapid, sensitive, and regenerable recognition of SARS-CoV-2 spike protein and human ferritin in lab-made samples. Those two are the target molecules of major importance for the rapid detection and monitoring of COVID-19-positive patients. For that purpose, monoclonal antibodies (mAbs) were bound to the scaffolds, resulting in a surface coverage of 436 ± 30 ng/cm2. KD affinity constants of 48.4 and 2.54 nM were obtained by surface plasmon resonance (SPR) spectroscopy for SARS-CoV-2 spike protein and human ferritin binding on these supramolecular scaffolds, respectively.


Subject(s)
Biomarkers/analysis , COVID-19/diagnosis , Graphite/chemistry , Immunoassay/methods , Spike Glycoprotein, Coronavirus/analysis , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/immunology , Ethylenes/chemistry , Ferritins/immunology , Ferritins/metabolism , Humans , Point-of-Care Systems , Polyamines/chemistry , Polyethylene Glycols/chemistry , Pyrenes/chemistry , Quantum Theory , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Semiconductors , Spike Glycoprotein, Coronavirus/immunology , Sulfonic Acids/chemistry , Surface Plasmon Resonance
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120237, 2022 Jan 05.
Article in English | MEDLINE | ID: covidwho-1380807

ABSTRACT

Here, we reported the synthesis of reduced porous graphene oxide (rPGO) decorated with gold nanoparticles (Au NPs) to modify the ITO electrode. Then we used this highly uniform Au NPs@rPGO modified ITO electrode as a surface-enhanced Raman spectroscopy-active surface and a working electrode. The uses of the Au nanoparticles and porous graphene enhance the Raman signals and the electrochemical conductivity. COVID-19 protein-based biosensor was developed based on immobilization of anti-COVID-19 antibodies onto the modified electrode and its uses as a probe for capturing the COVID-19 protein. The developed biosensor showed the capability of monitoring the COVID-19 protein within a concentration range from 100 nmol/L to 1 pmol/L with a limit of detection (LOD) of 75 fmol/L. Furthermore, COVID-19 protein was detected based on electrochemical techniques within a concentration range from 100 nmol/L to 500 fmol/L that showed a LOD of 39.5 fmol/L. Finally, three concentrations of COVID-19 protein spiked in human serum were investigated. Thus, the present sensor showed high efficiency towards the detection of COVID-19.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Metal Nanoparticles , Electrochemical Techniques , Electrodes , Gold , Humans , Porosity , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
13.
Adv Mater ; 33(40): e2102528, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1358054

ABSTRACT

Dendritic cell (DC) vaccines are used for cancer and infectious diseases, albeit with limited efficacy. Modulating the formation of DC-T-cell synapses may greatly increase their efficacy. The effects of graphene oxide (GO) nanosheets on DCs and DC-T-cell synapse formation are evaluated. In particular, size-dependent interactions are observed between GO nanosheets and DCs. GOs with diameters of >1 µm (L-GOs) demonstrate strong adherence to the DC surface, inducing cytoskeletal reorganization via the RhoA-ROCK-MLC pathway, while relatively small GOs (≈500 nm) are predominantly internalized by DCs. Furthermore, L-GO treatment enhances DC-T-cell synapse formation via cytoskeleton-dependent membrane positioning of integrin ICAM-1. L-GO acts as a "nanozipper," facilitating the aggregation of DC-T-cell clusters to produce a stable microenvironment for T cell activation. Importantly, L-GO-adjuvanted DCs promote robust cytotoxic T cell immune responses against SARS-CoV-2 spike 1, leading to >99.7% viral RNA clearance in mice infected with a clinically isolated SARS-CoV-2 strain. These findings highlight the potential value of nanomaterials as DC vaccine adjuvants for modulating DC-T-cell synapse formation and provide a basis for the development of effective COVID-19 vaccines.


Subject(s)
Adjuvants, Immunologic/therapeutic use , COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Dendritic Cells/immunology , Graphite/therapeutic use , Nanostructures/therapeutic use , Adjuvants, Immunologic/chemistry , Animals , COVID-19/immunology , COVID-19 Vaccines/immunology , Dendritic Cells/drug effects , Graphite/chemistry , Humans , Mice , Nanostructures/chemistry , SARS-CoV-2/immunology , T-Lymphocytes/drug effects , T-Lymphocytes/immunology
14.
Mater Sci Eng C Mater Biol Appl ; 129: 112356, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1340773

ABSTRACT

Recent COVID-19 pandemic has claimed millions of lives due to lack of a rapid diagnostic tool. Global scientific community is now making joint efforts on developing rapid and accurate diagnostic tools for early detection of viral infections to preventing future outbreaks. Conventional diagnostic methods for virus detection are expensive and time consuming. There is an immediate requirement for a sensitive, reliable, rapid and easy-to-use Point-of-Care (PoC) diagnostic technology. Electrochemical biosensors have the potential to fulfill these requirements, but they are less sensitive for sensing viruses/viral infections. However, sensitivity and performance of these electrochemical platforms can be improved by integrating carbon nanostructure, such as graphene and carbon nanotubes (CNTs). These nanostructures offer excellent electrical property, biocompatibility, chemical stability, mechanical strength and, large surface area that are most desired in developing PoC diagnostic tools for detecting viral infections with speed, sensitivity, and cost-effectiveness. This review summarizes recent advancements made toward integrating graphene/CNTs nanostructures and their surface modifications useful for developing new generation of electrochemical nanobiosensors for detecting viral infections. The review also provides prospects and considerations for extending the graphene/CNTs based electrochemical transducers into portable and wearable PoC tools that can be useful in preventing future outbreaks and pandemics.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Nanotubes, Carbon , Viruses , Humans , Pandemics , SARS-CoV-2
15.
ACS Appl Mater Interfaces ; 13(26): 30295-30305, 2021 Jul 07.
Article in English | MEDLINE | ID: covidwho-1337092

ABSTRACT

As viruses have been threatening global public health, fast diagnosis has been critical to effective disease management and control. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is now widely used as the gold standard for detecting viruses. Although a multiplex assay is essential for identifying virus types and subtypes, the poor multiplicity of RT-qPCR makes it laborious and time-consuming. In this paper, we describe the development of a multiplex RT-qPCR platform with hydrogel microparticles acting as independent reactors in a single reaction. To build target-specific particles, target-specific primers and probes are integrated into the particles in the form of noncovalent composites with boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs). The thermal release characteristics of DNA, primer, and probe from the composites of primer-BNNT and probe-CNT allow primer and probe to be stored in particles during particle production and to be delivered into the reaction. In addition, BNNT did not absorb but preserved the fluorescent signal, while CNT protected the fluorophore of the probe from the free radicals present during particle production. Bicompartmental primer-incorporated network (bcPIN) particles were designed to harness the distinctive properties of two nanomaterials. The bcPIN particles showed a high RT-qPCR efficiency of over 90% and effective suppression of non-specific reactions. 16-plex RT-qPCR has been achieved simply by recruiting differently coded bcPIN particles for each target. As a proof of concept, multiplex one-step RT-qPCR was successfully demonstrated with a simple reaction protocol.


Subject(s)
Hydrogels/chemistry , Multiplex Polymerase Chain Reaction/methods , Nanotubes, Carbon/chemistry , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Boron Compounds/chemistry , Coronavirus/chemistry , DNA Primers/chemistry , DNA, Single-Stranded/chemistry , Fluorescent Dyes/chemistry , Graphite/chemistry , Influenza A virus/chemistry , Newcastle disease virus/chemistry , Proof of Concept Study , RNA, Viral/chemistry , Virus Diseases/diagnosis
16.
Int J Mol Sci ; 22(13)2021 Jun 22.
Article in English | MEDLINE | ID: covidwho-1304656

ABSTRACT

The monolayer character of two-dimensional materials predestines them for application as active layers of sensors. However, their inherent high sensitivity is always accompanied by a low selectivity. Chemical functionalization of two-dimensional materials has emerged as a promising way to overcome the selectivity issues. Here, we demonstrate efficient graphene functionalization with carbohydrate ligands-chitooligomers, which bind proteins of the lectin family with high selectivity. Successful grafting of a chitooligomer library was thoroughly characterized, and glycan binding to wheat germ agglutinin was studied by a series of methods. The results demonstrate that the protein quaternary structure remains intact after binding to the functionalized graphene, and that the lectin can be liberated from the surface by the addition of a binding competitor. The chemoenzymatic assay with a horseradish peroxidase conjugate also confirmed the intact catalytic properties of the enzyme. The present approach thus paves the way towards graphene-based sensors for carbohydrate-lectin binding.


Subject(s)
Graphite/chemistry , Lectins/metabolism , Polysaccharides/chemistry , Horseradish Peroxidase , Lectins/analysis , Polysaccharides/metabolism , Protein Binding , Protein Structure, Quaternary
17.
Proc Natl Acad Sci U S A ; 118(30)2021 07 27.
Article in English | MEDLINE | ID: covidwho-1303827

ABSTRACT

COVID-19 has led to over 3.47 million deaths worldwide and continues to devastate primarily middle- and low-income countries. High-frequency testing has been proposed as a potential solution to prevent outbreaks. However, current tests are not sufficiently low-cost, rapid, or scalable to enable broad COVID-19 testing. Here, we describe LEAD (Low-cost Electrochemical Advanced Diagnostic), a diagnostic test that detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within 6.5 min and costs $1.50 per unit to produce using easily accessible and commercially available materials. LEAD is highly sensitive toward SARS-CoV-2 spike protein (limit of detection = 229 fg⋅mL-1) and displays an excellent performance profile using clinical saliva (100.0% sensitivity, 100.0% specificity, and 100.0% accuracy) and nasopharyngeal/oropharyngeal (88.7% sensitivity, 86.0% specificity, and 87.4% accuracy) samples. No cross-reactivity was detected with other coronavirus or influenza strains. Importantly, LEAD also successfully diagnosed the highly contagious SARS-CoV-2 B.1.1.7 UK variant. The device presents high reproducibility under all conditions tested and preserves its original sensitivity for 5 d when stored at 4 °C in phosphate-buffered saline. Our low-cost and do-it-yourself technology opens new avenues to facilitate high-frequency testing and access to much-needed diagnostic tests in resource-limited settings and low-income communities.


Subject(s)
Biosensing Techniques , COVID-19 Testing , COVID-19 , Graphite/chemistry , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , COVID-19/diagnosis , COVID-19/metabolism , Electrodes , Humans , Sensitivity and Specificity
18.
J Hazard Mater ; 420: 126570, 2021 10 15.
Article in English | MEDLINE | ID: covidwho-1293967

ABSTRACT

At present, it is very common to wear mask outdoors in order to avoid coronavirus disease 19 (COVID-19) infection. However, this leads to the formation of numerous plastic wastes that threaten humans and ecosystem. Against this major background, a novel co-pyrolysis coupled chemical vapor deposition (CVD) strategy is proposed to systematically convert mask and heavy fraction of bio-oil (HB) into biochar, bio-oil, and three-dimensional graphene films (3DGFs) is proposed. The biochar exhibits high higher heating value (HHV) (33.22-33.75 MJ/kg) and low ash content (2.34%), which is obviously superior to that of the walnut shell and anthracite coal. The bio-oil contains rich aromatic components, such as 1,2-dimethylbenzene and 2-methylnaphthalene, which can be used as chemical feedstock for insecticides. Furthermore, the 3DGF800 has a wide range of applications in the fields of oil spill cleanup and oil/water separation according to its fire resistance, high absorbability (40-89 g g-1) and long-term cycling stability. This research sheds new light on converting plastic wastes and industrial by-products into high added-value chemicals.


Subject(s)
COVID-19 , Graphite , Biofuels/analysis , Charcoal , Ecosystem , Hazardous Waste , Hot Temperature , Humans , Plant Oils , Polyphenols , SARS-CoV-2
19.
Carbohydr Polym ; 269: 118345, 2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1271581

ABSTRACT

This work reports novel chitosan functionalized graphene oxide (GO) nanocomposites combined fluorescence imaging and therapeutic functions in one agent, which can serve as a promising alternative to alleviate related diseases caused hyperinflammation. Briefly, GO was designed to be conjugated with chitosan, fluorescein-labeled peptide, toll-like receptor 4 antibody and hydroxycamptothecin/aloe emodin. We have demonstrated that such nanocomposites could effectively achieve active targeted delivery of pro-apoptotic and anti-inflammatory drugs into inflammatory cells and cause cells apoptosis by acid-responsive drug release. Moreover, confocal fluorescence imaging confirms that the drug-induced inflammatory cells apoptosis could be visualized the light-up fluorescence of fluorescein activated by caspase-3. Meanwhile, inflammatory-related biomarkers have down-regulated after the nanocomposites' treatment in both vitro and vivo experiments consistent with the results in histological sections. In summary, the bifunctional nanocomposites that possess anti-inflammation and fluorescence imaging could serve as a promising therapeutic agent for reducing hyperinflammation caused by numerous diseases.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Apoptosis/physiology , Drug Carriers/chemistry , Inflammation/drug therapy , Nanocomposites/chemistry , Animals , Anti-Inflammatory Agents/chemistry , Antibodies/immunology , Camptothecin/analogs & derivatives , Camptothecin/chemistry , Camptothecin/therapeutic use , Cattle , Cell Line , Chitosan/chemistry , Drug Liberation , Emodin/chemistry , Emodin/therapeutic use , Fluorescent Dyes/chemistry , Graphite/chemistry , Humans , Lipopolysaccharides , Mammary Glands, Human/drug effects , Mammary Glands, Human/pathology , Mastitis/chemically induced , Mastitis/drug therapy , Mastitis/pathology , Mice , Toll-Like Receptor 4/immunology
20.
Small ; 17(29): e2101508, 2021 07.
Article in English | MEDLINE | ID: covidwho-1263125

ABSTRACT

Abnormal elevated levels of cytokines such as interferon (IFN), interleukin (IL), and tumor necrosis factor (TNF), are considered as one of the prognosis biomarkers for indicating the progression to severe or critical COVID-19. Hence, it is of great significance to develop devices for monitoring their levels in COVID-19 patients, and thus enabling detecting COVID-19 patients that are worsening and to treat them before they become critically ill. Here, an intelligent aptameric dual channel graphene-TWEEN 80 field effect transistor (DGTFET) biosensing device for on-site detection of IFN-γ, TNF-α, and IL-6 within 7 min with limits of detection (LODs) of 476 × 10-15 , 608 × 10-15 , or 611 × 10-15 m respectively in biofluids is presented. Using the customized Android App together with this intelligent device, asymptomatic or mild COVID-19 patients can have a preliminary self-detection of cytokines and get a warning reminder while the condition starts to deteriorate. Also, the device can be fabricated on flexible substrates toward wearable applications for moderate or even critical COVID-19 cases for consistently monitoring cytokines under different deformations. Hence, the intelligent aptameric DGTFET biosensing device is promising to be used for point-of-care applications for monitoring conditions of COVID-19 patients who are in different situations.


Subject(s)
COVID-19 , Graphite , Biomarkers , Cytokine Release Syndrome , Cytokines , Humans , Interleukin-6 , SARS-CoV-2
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