Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
1.
Mikrochim Acta ; 189(3): 125, 2022 03 01.
Article in English | MEDLINE | ID: covidwho-1712245

ABSTRACT

A novel electrochemical sensor is reported for the detection of the antiviral drug favipiravir based on the core-shell nanocomposite of flower-like molybdenum disulfide (MoS2) nanospheres and molecularly imprinted polymers (MIPs). The MoS2@MIP core-shell nanocomposite was prepared via the electrodeposition of a MIP layer on the MoS2 modified electrode, using o-phenylenediamine as the monomer and favipiravir as the template. The selective binding of target favipiravir at the MoS2@MIP core-shell nanocomposite produced a redox signal in a concentration dependent manner, which was used for the quantitative analysis. The preparation process of the MoS2@MIP core-shell nanocomposite was optimized. Under the optimal conditions, the sensor exhibited a wide linear response range of 0.01 ~ 100 nM (1.57*10-6 ~ 1.57*10-2 µg mL-1) and a low detection limit of 0.002 nM (3.14*10-7 µg mL-1). Application of the sensor was demonstrated by detecting favipiravir in a minimum amount of 10 µL biological samples (urine and plasma). Satisfied results in the recovery tests indicated a high potential of favipiravir monitoring in infectious COVID-19 samples.


Subject(s)
Amides/analysis , Antiviral Agents/analysis , Disulfides/chemistry , Molecularly Imprinted Polymers/chemistry , Molybdenum/chemistry , Nanocomposites/chemistry , Nanospheres/chemistry , Pyrazines/analysis , Amides/blood , Amides/therapeutic use , Amides/urine , Antiviral Agents/blood , Antiviral Agents/therapeutic use , Antiviral Agents/urine , COVID-19/drug therapy , COVID-19/virology , Electrochemical Techniques/methods , Humans , Limit of Detection , Oxidation-Reduction , Pyrazines/blood , Pyrazines/therapeutic use , Pyrazines/urine , Reproducibility of Results , SARS-CoV-2/isolation & purification
2.
ACS Appl Mater Interfaces ; 14(8): 10844-10855, 2022 Mar 02.
Article in English | MEDLINE | ID: covidwho-1692677

ABSTRACT

The widespread and long-lasting effect of the COVID-19 pandemic has called attention to the significance of technological advances in the rapid diagnosis of SARS-CoV-2 virus. This study reports the use of a highly stable buffer-based zinc oxide/reduced graphene oxide (bbZnO/rGO) nanocomposite coated on carbon screen-printed electrodes for electrochemical immuno-biosensing of SARS-CoV-2 nuelocapsid (N-) protein antigens in spiked and clinical samples. The incorporation of a salt-based (ionic) matrix for uniform dispersion of the nanomixture eliminates multistep nanomaterial synthesis on the surface of the electrode and enables a stable single-step sensor nanocoating. The immuno-biosensor provides a limit of detection of 21 fg/mL over a linear range of 1-10 000 pg/mL and exhibits a sensitivity of 32.07 ohms·mL/pg·mm2 for detection of N-protein in spiked samples. The N-protein biosensor is successful in discriminating positive and negative clinical samples within 15 min, demonstrating its proof of concept used as a COVID-19 rapid antigen test.


Subject(s)
Antigens, Viral/analysis , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/analysis , Graphite/chemistry , Nanocomposites/chemistry , Zinc Oxide/chemistry , Antibodies, Immobilized/immunology , Antigens, Viral/immunology , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Coronavirus Nucleocapsid Proteins/immunology , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Electrodes , Humans , Immunoassay/instrumentation , Immunoassay/methods , Limit of Detection , Phosphoproteins/analysis , Phosphoproteins/immunology , Proof of Concept Study , SARS-CoV-2/chemistry
3.
Sci Rep ; 11(1): 24318, 2021 12 21.
Article in English | MEDLINE | ID: covidwho-1585786

ABSTRACT

The COVID-19 pandemic presents a unique challenge to the healthcare community due to the high infectivity rate and need for effective personal protective equipment. Zinc oxide nanoparticles have shown promising antimicrobial properties and are recognized as a safe additive in many food and cosmetic products. This work presents a novel nanocomposite synthesis approach, which allows zinc oxide nanoparticles to be grown within textile and face mask materials, including melt-blown polypropylene and nylon-cotton. The resulting nanocomposite achieves greater than 3 log10 reduction (≥ 99.9%) in coronavirus titer within a contact time of 10 min, by disintegrating the viral envelope. The new nanocomposite textile retains activity even after 100 laundry cycles and has been dermatologist tested as non-irritant and hypoallergenic. Various face mask designs were tested to improve filtration efficiency and breathability while offering antiviral protection, with Claros' design reporting higher filtration efficiency than surgical masks (> 50%) for particles ranged 200 nm to 5 µm in size.


Subject(s)
Masks/virology , Nanocomposites/toxicity , SARS-CoV-2/drug effects , Virus Inactivation/drug effects , COVID-19/prevention & control , COVID-19/virology , Filtration/methods , Humans , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Nylons/chemistry , Polypropylenes/chemistry , SARS-CoV-2/isolation & purification , Textiles/analysis , Zinc Oxide/chemistry
4.
Int J Mol Sci ; 22(24)2021 Dec 18.
Article in English | MEDLINE | ID: covidwho-1580689

ABSTRACT

Global reports on multidrug resistance (MDR) and life-threatening pathogens such as SARS-CoV-2 and Candida cruris have stimulated researchers to explore new antimicrobials that are eco-friendly and economically viable. In this context, biodegradable polymers such as nisin, chitin, and pullulan play an important role in solving the problem. Pullulan is an important edible, biocompatible, water-soluble polymer secreted by Aureobasidium pullulans that occurs ubiquitously. It consists of maltotriose units linked with α-1,6 glycosidic bonds and is classed as Generally Regarded as Safe (GRAS) by the Food and Drug Administration (FDA) in the USA. Pullulan is known for its antibacterial, antifungal, antiviral, and antitumor activities when incorporated with other additives such as antibiotics, drugs, nanoparticles, and so on. Considering the importance of its antimicrobial activities, this polymer can be used as a potential antimicrobial agent against various pathogenic microorganisms including the multidrug-resistant (MDR) pathogens. Moreover, pullulan has ability to synthesize biogenic silver nanoparticles (AgNPs), which are remarkably efficacious against pathogenic microbes. The pullulan-based nanocomposites can be applied for wound healing, food packaging, and also enhancing the shelf-life of fruits and vegetables. In this review, we have discussed biosynthesis of pullulan and its role as antibacterial, antiviral, and antifungal agent. Pullulan-based films impregnated with different antimicrobials such as AgNPs, chitosan, essential oils, and so on, forming nanocomposites have also been discussed as natural alternatives to combat the problems posed by pathogens.


Subject(s)
Anti-Infective Agents/pharmacology , Drug Resistance, Multiple/drug effects , Glucans/biosynthesis , Anti-Bacterial Agents , Anti-Infective Agents/chemistry , Antifungal Agents , COVID-19 , Chitin/pharmacology , Chitosan/chemistry , Drug Resistance, Multiple/physiology , Food Packaging , Glucans/metabolism , Glucans/pharmacology , Humans , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Nisin/pharmacology , Polymers/chemistry , SARS-CoV-2
5.
Mikrochim Acta ; 188(12): 434, 2021 11 27.
Article in English | MEDLINE | ID: covidwho-1536308

ABSTRACT

A novel and sensitive voltammetric nanosensor was developed for the first time for trace level monitoring of favipiravir based on gold/silver core-shell nanoparticles (Au@Ag CSNPs) with conductive polymer poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) and functionalized multi carbon nanotubes (F-MWCNTs) on a glassy carbon electrode (GCE). The formation of Au@Ag CSNPs/PEDOT:PSS/F-MWCNT composite was confirmed by various analytical techniques, including X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and field-emission scanning electron microscopy (SEM). Under the optimized conditions and at a typical working potential of + 1.23 V (vs. Ag/AgCl), the Au@Ag CSNPs/PEDOT:PSS/F-MWCNT/GCE revealed linear quantitative ranges from 0.005 to 0.009 and 0.009 to 1.95 µM with a limit of detection 0.46 nM (S/N = 3) with acceptable relative standard deviations (1.1-4.9 %) for pharmaceutical formulations, urine, and human plasma samples without applying any sample pretreatment (1.12-4.93%). The interference effect of antiviral drugs, biological compounds, and amino acids was negligible, and the sensing system demonstrated outstanding reproducibility, repeatability, stability, and reusability. The findings revealed that this assay strategy has promising applications in diagnosing FAV in clinical samples, which could be attributed to the large surface area on active sites and high conductivity of bimetallic nanocomposite.


Subject(s)
Amides/pharmacology , Antiviral Agents/pharmacology , COVID-19/drug therapy , Electrochemistry/methods , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Nanomedicine/methods , Nanotechnology/methods , Pyrazines/pharmacology , Colloids/chemistry , Electrodes , Gold/chemistry , Humans , Limit of Detection , Linear Models , Nanotubes , Polymers/chemistry
6.
Sci Rep ; 11(1): 22543, 2021 11 19.
Article in English | MEDLINE | ID: covidwho-1526103

ABSTRACT

Microbial contamination is one of the major dreadful problems that raises hospitalization, morbidity and mortality rates globally, which subsequently obstructs socio-economic progress. The continuous misuse and overutilization of antibiotics participate mainly in the emergence of microbial resistance. To circumvent such a multidrug-resistance phenomenon, well-defined nanocomposite structures have recently been employed. In the current study, a facile, novel and cost-effective approach was applied to synthesize Ag@Ag2O core-shell nanocomposites (NCs) via chemical method. Several techniques were used to determine the structural, morphological, and optical characteristics of the as-prepared NCs. XRD, Raman, FTIR, XPS and SAED analysis revealed a crystalline hybrid structure of Ag core and Ag2O shell. Besides, SEM and HRTEM micrographs depicted spherical nanoparticles with size range of 19-60 nm. Additionally, zeta potential and fluorescence spectra illustrated aggregated nature of Ag@Ag2O NCs by - 5.34 mV with fluorescence emission peak at 498 nm. Ag@Ag2O NCs exhibited higher antimicrobial, antibiofilm, and algicidal activity in dose-dependent behavior. Interestingly, a remarkable mycocidal potency by 50 µg of Ag@Ag2O NCs against Candida albican; implying promising activity against COVID-19 white fungal post-infections. Through assessing cytotoxicity, Ag@Ag2O NCs exhibited higher safety against Vero cells than bulk silver nitrate by more than 100-fold.


Subject(s)
Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Biofilms/drug effects , Nanocomposites/chemistry , Oxides/chemistry , Silver Compounds/chemistry , Animals , Anti-Infective Agents/chemical synthesis , Candida albicans/drug effects , Cell Survival/drug effects , Chlorella vulgaris/drug effects , Chlorocebus aethiops , Disinfectants/chemical synthesis , Disinfectants/chemistry , Disinfectants/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Metal Nanoparticles/chemistry , Oxides/chemical synthesis , Pseudomonas aeruginosa/drug effects , Silver Compounds/chemical synthesis , Silver Nitrate/pharmacology , Staphylococcus aureus/drug effects , Vero Cells
7.
Molecules ; 25(20)2020 Oct 13.
Article in English | MEDLINE | ID: covidwho-1305732

ABSTRACT

Nano-islands are entities (droplets or other shapes) that are formed by spontaneous dewetting (agglomeration, in the early literature) of thin and very thin metallic (especially gold) films on a substrate, done by post-deposition heating or by using other sources of energy. In addition to thermally generated nano-islands, more recently, nanoparticle films have also been dewetted, in order to form nano-islands. The localized surface plasmon resonance (LSPR) band of gold nano-islands was found to be sensitive to changes in the surrounding environment, making it a suitable platform for sensing and biosensing applications. In this review, we revisit the development of the concept of nano-island(s), the thermodynamics of dewetting of thin metal films, and the effect of the substrate on the morphology and optical properties of nano-islands. A special emphasis is made on nanoparticle films and their applications to biosensing, with ample examples from the authors' work.


Subject(s)
Gold/chemistry , Nanocomposites/chemistry , Point-of-Care Systems , Surface Plasmon Resonance/instrumentation , Animals , Biosensing Techniques/instrumentation , Growth Hormone/analysis , Humans , Lab-On-A-Chip Devices , Milk/chemistry , Nanotechnology/methods , Surface Plasmon Resonance/methods
8.
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
9.
Sci Rep ; 11(1): 8692, 2021 04 22.
Article in English | MEDLINE | ID: covidwho-1199310

ABSTRACT

A metal nanoparticle composite, namely TPNT1, which contains Au-NP (1 ppm), Ag-NP (5 ppm), ZnO-NP (60 ppm) and ClO2 (42.5 ppm) in aqueous solution was prepared and characterized by spectroscopy, transmission electron microscopy, dynamic light scattering analysis and potentiometric titration. Based on the in vitro cell-based assay, TPNT1 inhibited six major clades of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with effective concentration within the range to be used as food additives. TPNT1 was shown to block viral entry by inhibiting the binding of SARS-CoV-2 spike proteins to the angiotensin-converting enzyme 2 (ACE2) receptor and to interfere with the syncytium formation. In addition, TPNT1 also effectively reduced the cytopathic effects induced by human (H1N1) and avian (H5N1) influenza viruses, including the wild-type and oseltamivir-resistant virus isolates. Together with previously demonstrated efficacy as antimicrobials, TPNT1 can block viral entry and inhibit or prevent viral infection to provide prophylactic effects against both SARS-CoV-2 and opportunistic infections.


Subject(s)
Gold/pharmacology , Influenza A Virus, H1N1 Subtype/physiology , Influenza A Virus, H5N1 Subtype/physiology , SARS-CoV-2/physiology , Silver/pharmacology , Zinc Oxide/pharmacology , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Drug Resistance, Viral/drug effects , Food Additives/pharmacology , Gold/chemistry , HEK293 Cells , Humans , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H5N1 Subtype/drug effects , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Oseltamivir/pharmacology , Particle Size , Protein Binding/drug effects , SARS-CoV-2/drug effects , Silver/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects , Zinc Oxide/chemistry
10.
ACS Appl Mater Interfaces ; 13(17): 19816-19824, 2021 May 05.
Article in English | MEDLINE | ID: covidwho-1199255

ABSTRACT

The detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for preventing and controlling infectious diseases and disease treatment. In this work, a Au@Ti3C2@PEI-Ru(dcbpy)32+ nanocomposite-based electrochemiluminescence (ECL) biosensor was rationally designed, which realized sensitive detection of the RNA-dependent RNA polymerase (RdRp) gene of SARS-CoV-2. In addition, a DNA walker was also used to excise the hairpin DNAs under the action of Nb.BbvCI endonuclease. Furthermore, model DNA-Ag nanoclusters (model DNA-AgNCs) were used to quench the initial ECL signal. As a result, the ECL biosensor was used to sensitively detect the SARS-CoV-2 RdRp gene with a detection range of 1 fM to 100 pM and a limit of detection of 0.21 fM. It was indicated that the ECL biosensor had a great application potential for clinical medical detection. Furthermore, the DNA walker amplification also played a reliable candidate strategy for other detection methods.


Subject(s)
Biosensing Techniques/methods , Nanocomposites/chemistry , SARS-CoV-2/genetics , DNA, Viral/genetics , RNA-Dependent RNA Polymerase/metabolism
11.
Inorg Chem ; 60(9): 6585-6599, 2021 May 03.
Article in English | MEDLINE | ID: covidwho-1195597

ABSTRACT

Silver vanadate nanorods (ß-AgVO3) with silver nanoparticles (Ag-NPs) decorated on the surface of the rods were synthesized by using simple hydrothermal technique and later anchored onto nitrogen-doped reduced graphene oxide (N-rGO) to make a novel nanocomposite. Experimental analyses were carried out to identify the electronic configuration by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis, which revealed monoclinic patterns of the C12/m1 space group with Wulff construction forming beta silver vanadate (ß-AgVO3) crystals with optical density and phase transformations. Ag nucleation showed consistent results with metallic formation and electronic changes occurring in [AgO5] and [AgO3] clusters. Transmission electron microscopy and field-emission scanning electron microscopy with elemental mapping and EDX analysis of the morphology reveals the nanorod structure for ß-AgVO3 with AgNPs on the surface and sheets for N-rGO. Additionally, a novel electrochemical sensor is constructed by using Ag/AgVO3/N-rGO on screen-printed carbon paste electrodes for the detection of antiviral drug levofloxacin (LEV) which is used as a primary antibiotic in controlling COVID-19. Using differential pulse voltammetry, LEV is determined with a low detection limit of 0.00792 nm for a linear range of 0.09-671 µM with an ultrahigh sensitivity of 152.19 µA µM-1 cm-2. Furthermore, modified electrode performance is tested by real-time monitoring using biological and river samples.


Subject(s)
Dielectric Spectroscopy/instrumentation , Dielectric Spectroscopy/methods , Levofloxacin/analysis , Nanocomposites/chemistry , Antiviral Agents/analysis , Antiviral Agents/blood , Antiviral Agents/urine , Carbon/chemistry , Electrodes , Graphite/chemistry , Humans , Levofloxacin/blood , Levofloxacin/urine , Limit of Detection , Metal Nanoparticles/chemistry , Microscopy, Electron, Transmission , Nanotubes/chemistry , Photoelectron Spectroscopy , Silver/chemistry , Silver Compounds/chemistry , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman , Tablets , Vanadates/chemistry , X-Ray Diffraction
12.
Nano Lett ; 21(4): 1576-1583, 2021 02 24.
Article in English | MEDLINE | ID: covidwho-960293

ABSTRACT

Recently, bioaerosols, including the 2019 novel coronavirus, pose a serious threat to global public health. Herein, we introduce a visible-light-activated (VLA) antimicrobial air filter functionalized with titanium dioxide (TiO2)-crystal violet (CV) nanocomposites facilitating abandoned visible light from sunlight or indoor lights. The TiO2-CV based VLA antimicrobial air filters exhibit a potent inactivation rate of ∼99.98% and filtration efficiency of ∼99.9% against various bioaerosols. Under visible-light, the CV is involved in overall inactivation by inducing reactive oxygen species production both directly (CV itself) and indirectly (in combination with TiO2). Moreover, the susceptibility of the CV to humidity was significantly improved by forming a hydrophobic molecular layer on the TiO2 surface, highlighting its potential applicability in real environments such as exhaled or humid air. We believe this work can open a new avenue for designing and realizing practical antimicrobial technology using ubiquitous visible-light energy against the threat of infectious bioaerosols.


Subject(s)
Air Microbiology , Anti-Infective Agents, Local/chemistry , Disinfection/methods , Gentian Violet/chemistry , Nanocomposites/chemistry , Titanium/chemistry , Anti-Infective Agents, Local/pharmacology , Bacteria/drug effects , Bacteria/radiation effects , Bacterial Infections/prevention & control , COVID-19/prevention & control , Disinfection/instrumentation , Filtration/instrumentation , Filtration/methods , Gentian Violet/pharmacology , Humans , Light , Nanocomposites/ultrastructure , Titanium/pharmacology , Water/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL