RESUMEN
Dengue fever is a global mosquito-borne viral infectious disease that has, in recent years, rapidly spread to almost all regions of the world. Lack of vaccination and directed treatment makes detection at the infection's early stages extremely important for disease prevention and clinical care. In this paper, we developed a rapid and highly sensitive dengue detection tool using a novel platform of diagnosis, called spin-enhanced lateral flow immunoassay (SELFIA) with a fluorescent nanodiamond (FND) as a reporter. Taking advantage of the unique magneto-optical properties of negatively charged nitrogen-vacancy centers in the FND, the SELFIA platform utilizes alternating electromagnetic fields to modulate signals from FND's fluorescence to provide sensitive and specific results. With sandwich SELFIA, we could efficiently detect all four dengue non-structural protein (NS1) serotypes (DV1, DV2, DV3, and DV4). The lowest detection concentration of the dengue NS1 antigens varied from 0.1 to 1.3 ng/mL, which is among the lowest limits of detection to date. The FND-based SELFIA technique is up to 500 and 5000 times more sensitive than carbon black and conventional gold nanoparticles, respectively. By using different anti-NS1 antibodies, we could differentiate the NS1 antigen serotypes contained in the tested samples via three simultaneous assays. Proposed SELFIA allows for both qualitative and quantitative differentiation between different NS1 protein serotypes, which will assist in the development of a highly sensitive and specific detection platform for dengue screening that has the potential to detect the disease at its early stages, especially in high-risk and limited-resource areas.
Asunto(s)
Virus del Dengue , Dengue , Nanopartículas del Metal , Animales , Humanos , Serogrupo , Oro , Proteínas no Estructurales Virales , Inmunoensayo/métodos , Anticuerpos Antivirales , Dengue/diagnóstico , Sensibilidad y Especificidad , Ensayo de Inmunoadsorción Enzimática/métodosRESUMEN
Environmental contamination and energy shortage are among the most critical global issues that require urgent solutions to ensure sustainable ecological balance. Rapid and ultrasensitive monitoring of water quality against pollutant contaminations using a low-cost, easy-to-operate, and environmentally friendly technology is a promising yet not commonly available solution. Here, we demonstrate the effective use of plasma-converted natural bioresources for environmental monitoring. The energy-efficient microplasmas operated at ambient conditions are used to convert diverse bioresources, including fructose, chitosan, citric acid, lignin, cellulose, and starch, into heteroatom-doped graphene quantum dots (GQDs) with controlled structures and functionalities for applications as fluorescence-based environmental nanoprobes. The simple structure of citric acid enables the production of monodispersed 3.6 nm averaged-size GQDs with excitation-independent emissions, while the saccharides including fructose, chitosan, lignin, cellulose, and starch allow the synthesis of GQDs with excitation-dependent emissions due to broader size distribution. Moreover, the presence of heteroatoms such as N and/or S in the chemical structures of chitosan and lignin coupled with the highly reactive species generated by the plasma facilitates the one-step synthesis of N, S-codoped GQDs, which offer selective detection of toxic environmental contaminants with a low limit of detection of 7.4 nM. Our work provides an insight into the rapid and green fabrication of GQDs with tunable emissions from natural resources in a scalable and sustainable manner, which is expected to generate impact in the environmental safety, energy conversion and storage, nanocatalysis, and nanomedicine fields.
Asunto(s)
Quitosano , Grafito , Puntos Cuánticos , Puntos Cuánticos/química , Grafito/química , Lignina , Nitrógeno/química , Ácido Cítrico/química , Almidón , FructosaRESUMEN
SARS-CoV-2 viruses, responsible for the COVID-19 pandemic, continues to evolve into new mutations, which poses a significant threat to public health. Current testing methods have some limitations, such as long turnaround times, high costs, and professional laboratory requirements. In this report, the novel Spin-Enhanced Lateral Flow Immunoassay (SELFIA) platform and fluorescent nanodiamond (FND) reporter were utilized for the rapid detection of SARS-CoV-2 nucleocapsid and spike antigens from different variants, including wild-type (Wuhan-1), Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron (B.1.1.529). The SARS-CoV-2 antibodies were conjugated with FND via nonspecific binding, enabling the detection of SARS-CoV-2 antigens via both direct and competitive SELFIA format. Direct SELFIA was performed by directly adding the SARS-CoV-2 antibodies-conjugated FND on the antigens-immobilized nitrocellulose (NC) membrane. Conversely, the SARS-CoV-2 antigen-containing sample was first incubated with the antibodies-conjugated FND, and then dropped on the antigen-immobilized NC membrane to carry out the competitive SELFIA. The results suggested that S44F anti-S IgG antibody can be efficiently used for the detection of wild-type, Alpha, Delta, and Omicron variants spike antigens. Findings were comparable in direct SELFIA, competitive SELFIA, and ELISA. A detection limit of 1.94, 0.77, 1.14, 1.91, and 1.68 ng/mL can be achieved for SARS-CoV-2 N protein, wild-type, Alpha, Delta, and Omicron S proteins, respectively, via competitive SELFIA assay. These results suggest that a direct SELFIA assay can be used for antibody/antigen pair screening in diagnosis development, while the competitive SELFIA assay can serve as an accurate quantitative diagnostic tool. The simplicity and rapidity of the SELFIA platform were demonstrated, which can be leveraged in the detection of other infectious diseases in the near future.
Asunto(s)
COVID-19 , Nanodiamantes , Anticuerpos Antivirales , COVID-19/diagnóstico , Colodión , Humanos , Inmunoensayo/métodos , Inmunoglobulina G , Pandemias , SARS-CoV-2 , Glicoproteína de la Espiga del CoronavirusRESUMEN
In this study, several types of Artemisia annua in soil, including the soil which had not been planted, or planted for one year, or continuously planted for three or five years were collected, in order to study the influences of continuous cropping on the growth of A. annua, content of artemisinin, available nutrient of soil, and bacterial community structure through adopting routine analysis and Illumina MiSeq high-throughput sequencing. The results showed that continuous cropping inhibited significantly the growth of A. annua and reduced leaf biomass, content and yield of artemisinin, with the maximum decreasing amplitude of 30.20%, 7.70% and 35.58% respectively. The content of soil organic matter, available nitrogen, available phosphorus and 16S rRNA sequence number were increased to different extents after continuous cropping of A. annua. According to the results of high-throughput sequencing, 634-812 types of common bacteria belonged to 21 categories were planted in different soil of A. annua with different planting years, which represented that the distribution distance of the point of bacterial community with different years among coordinate system of principal component was relative distant, and community structure had significant changes (P<0.05). As the planting years increased, the abundance of Actinobacteria, Chloroflexi, Gemmatimonadetes decreased in contrast to Proteobacteria, Acidobacteria and Verrucomicrobia. In the top 20 types of predominant bacteria,Nitrospira japonica and Nitrospira disappeared, among which, only Gemmatimonadaceae, Micromonosporaceae, Nitrosomonadaceae, Xanthobacteraceae, and unculture bacterium JG30-KF-AS9 were similar, indicating that the planting and continuous cropping of A. annua selectively inhibited the growth and reproduction of soil bacteria, and influenced the supply and transform of soil nutrient, leading to a poor growth and resulting in reduction of artemisinin content and yield. Therefore, it is necessary to advocate crop rotation in the process of planting A. annua.
Asunto(s)
Agricultura/métodos , Artemisia annua/crecimiento & desarrollo , Bacterias/clasificación , Microbiología del Suelo , Artemisia annua/química , Artemisininas/análisis , ARN Ribosómico 16SRESUMEN
The paper is aimed to study the distribution, population density, soil conditions and community characteristics of accompanying plants' in Enshi sub-regional different areas, with a typical habitats investigation method. The results showed that the wild Panax japonicus mainly distributed in moist places under the forests, by streams, or secondary forests of high grass, within east longitude 29°-30°, north latitude 108°-110°and about 1 000-15 00 meters above sea level. The soils were mainly tide soil and humus with yellow-brown soil, yellow soil and red soil, and the humus thickness was5-30 centimeter, pH 6.0-6.8, the moisture content of 16.8%-24.2%, soil bulk density of 1.39-2.12. Its geographical vegetation types were mainly evergreen coniferous forest, evergreen-deciduous mixture broad leaved forest and evergreen coniferous forest mixed deciduous broad-leaved forest, including three levels community structure of arbors, shrubs and herbaceous; Its accompanying plants reached 86 families, 118 genera, 134 species of seed plants, the arbors included 15 families, 21 genera, 26 species and the dominant species community mainly Pinaceae such as Pinus massoniana, P. tabuliformis, P. henryi and Taxodiaceae such as Cunninghamia lanceolata, Cryptomeria fortunei etc. The shrubs included 39 families, 54 genera, 62 species with the dominant species such as Camellia oleifera, Kalopanax septemlobus, Akebia trifoliata, Trachycarpusfortunei, Rhamnus globosa, Smilax corbularia and so on. The herbaceous included 32 families, 43 genera, 46 species, and Ferns such as the black-footed Dryopteris, Dryopteris crassirhizom, Coniogramme affinis, Polystichum tripteron, Adiantum pedatum, Lunathyrium acrostichoides, Woodsia ilvensis and Woodwardia japonica were dominant species. The cover layer covered a large number of lichens and mosses. The wild P. japonicus can be found among the P. massoniana, P. tabuliformis, P. henryi, lichens and mosses. These may indicate that the wild P. japonicusin Enshi requires higher demands on the ecological environment, its accompanying plants are mainly the tree layer-shrub layer-herb layer, and vertical structure is obvious. The study provides a basis for domestication and conservation of P. japonicus resources.