Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Ecol Lett ; 27(6): e14447, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38844351

RESUMEN

Host specialization plays a critical role in the ecology and evolution of plant-microbe symbiosis. Theory predicts that host specialization is associated with microbial genome streamlining and is influenced by the abundance of host species, both of which can vary across latitudes, leading to a latitudinal gradient in host specificity. Here, we quantified the host specificity and composition of plant-bacteria symbioses on leaves across 329 tree species spanning a latitudinal gradient. Our analysis revealed a predominance of host-specialized leaf bacteria. The degree of host specificity was negatively correlated with bacterial genome size and the local abundance of host plants. Additionally, we found an increased host specificity at lower latitudes, aligning with the high prevalence of small bacterial genomes and rare host species in the tropics. These findings underscore the importance of genome streamlining and host abundance in the evolution of host specificity in plant-associated bacteria along the latitudinal gradient.


Asunto(s)
Tamaño del Genoma , Especificidad del Huésped , Hojas de la Planta , Simbiosis , Hojas de la Planta/microbiología , Bacterias/genética , Bacterias/clasificación , Genoma Bacteriano , Árboles/microbiología
2.
Proc Biol Sci ; 291(2027): 20240206, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39043235

RESUMEN

Sulfur (S) is an essential bioelement with vital roles in serving regulatory and catalytic functions and tightly coupled with N and P in plants. However, globally stoichiometric patterns of leaf S and its relationships to leaf N and P are less well studied. We compiled 31 939 records of leaf-based data for 2600 plant species across 6652 sites worldwide. All plant species were divided into different phylogenetic taxa and growth forms. Standard major axis analysis was employed to fit the bivariate element relationships. A phylogenetic linear mixed-effect model and a multiple-regression model were used to partition the variations of bioelements into phylogeny and environments, and then to estimate the importance of environmental variables. Global geometric mean leaf S, N and P concentrations were 1.44, 15.70 and 1.27 mg g-1, respectively, with significant differences among plant groups. Leaf S-N-P positively correlated with each other, ignoring plant groups. The scaling exponents of LN-LS, LP-LS and LN-LP were 0.64, 0.76 and 0.79, respectively, for all species, but differed among plant groups. Both phylogeny and environments regulated the bioelements. The variability, rather than mean temperature, controlled the bioelements. Phylogeny explained more for the concentrations of all the three bioelements than environments, of which S was the one most affected by phylogenetic taxa.


Asunto(s)
Nitrógeno , Fósforo , Filogenia , Hojas de la Planta , Azufre , Fósforo/metabolismo , Azufre/metabolismo , Nitrógeno/metabolismo , Plantas , Ambiente
3.
Anal Chem ; 95(37): 14119-14126, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37683257

RESUMEN

The building of practical biosensors that have anti-interference abilities against biofouling of nonspecific proteins and biooxidation of reducing agents in actual biological matrixes remains a great challenge. Herein, a robust photoelectrochemical (PEC) biosensor capable of accurate detection in human serum was pioneered through the integration of a new engineered branching peptide (EBP) into a synergetic dual-photoelectrode system. The synergetic dual-photoelectrode system involved the tandem connection of a C3N4/TiO2 photoanode and a AuPt/PANI photocathode, while the EBP as a dual-functional antifouling and recognition probe featured an inverted Y-shaped configuration with one recognition backbone and two antifouling branches. Such an EBP enables a simple procedure for electrode modification and an enhanced antifouling nature compared to a regular linear peptide (LP), as theoretically supported by the results from molecular dynamics simulations. The as-developed PEC biosensor had a higher photocurrent response and a good antioxidation property inherited from the photoanode and photocathode, respectively. Targeting the model protein biomarker of cardiac troponin I (cTnI), this biosensor achieved good performances in terms of high sensitivity, specificity, and anti-interference.


Asunto(s)
Incrustaciones Biológicas , Humanos , Incrustaciones Biológicas/prevención & control , Péptidos , Troponina I , Antioxidantes , Electrodos
4.
Anal Chem ; 95(31): 11723-11731, 2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37493946

RESUMEN

Here, a novel rapid and ultrasensitive aptamer biosensor was designed for target-induced activation of AIE effect and followed by the activation of Crispr Cas12a (LbCpf1)-mediated cleavage to achieve dual-signal detection. The prepared DNA building blocks contain the target aptamer, ssDNA-Fc, and Activator1. In this system, the activation mode was divided into two steps. First, when the target interacts with the aptamers, the DNA building blocks would be disintegrated rapidly, releasing a mass of Ac1, generating ETTC-dsDNA aggregated to produce a fluorescence signal by the AIE effect. Second, with the release of Ac2, LbCpf1-crRNA was activated, which greatly improves the ssDNA-Fc cleavage efficiency to render signal amplification and ultrasensitive detection of the target. Satisfactorily, using this approach to detect gliotoxin, optimal conditions for detection was achieved for reducing the detection time to 55 min, achieving a low detection limit of 2.4 fM and a satisfactory linear in the range of 50 fM to 1 nM, which addressed the shortcoming of a weak electrochemical signal in previous sensors. The water-insoluble AIE material was coupled with DNA to obtain water-soluble ETTC-dsDNA and successfully introduced into the sensor system, with a low detection limit of 5.6 fM. Subsequently, the biosensor combined with handheld electrochemical workstation was successfully applied in the detection of gliotoxin in five actual samples, with a detection range of 32.0 to 2.09 × 108 pM. This strategy not only provides a novel and effective detection platform for mycotoxins in complex food matrices but also opens a promising avenue for various molecules detection in imaging and disease diagnosis.


Asunto(s)
Técnicas Biosensibles , Gliotoxina , Micotoxinas , Sistemas CRISPR-Cas , Oligonucleótidos , ADN de Cadena Simple
5.
Anal Chem ; 95(29): 11091-11098, 2023 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-37439630

RESUMEN

The construction of low-fouling biosensors for assaying biomarkers in complex biological samples remains a challenge, and the key limitation is the lack of effective anti-fouling materials. Inspired by the biomimetic process of protein phosphorylation, we herein designed a new phosphorylated peptide modified with the dihydrogen phosphate (-PO4H2) group, which significantly increased the hydrophilicity and anti-fouling capability of the peptide when compared with natural and normal peptides. Molecular simulation (MS) illustrated that, compared with the -COOH and -NH2 groups, the -PO4H2 group formed the most numbers of hydrogen bonds and stronger hydrogen bonds with water molecules. As a result, the PO4H2-oligopeptide was proved by MS to be able to attract the greatest number of water molecules, so as to form a compact layer of H2O to resist further adsorption of nonspecific biomolecules. The modification of electrodes with the designed PO4H2-oligopeptides, in addition to the adoption of neutral peptide nucleic acids (PNAs) as the sensing probes, ensured the fabrication of anti-fouling electrochemical biosensors capable of detecting nucleic acids in complex saliva. The constructed anti-fouling biosensor was able to detect the nucleic acid of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in undiluted saliva, with a wide linear response range (0.01 pM-0.01 µM) and a low limit of detection (LOD) of 3.4 fM (S/N = 3). The phosphorylation of oligopeptides offers an effective strategy to designing ultra-hydrophilic peptides suitable for the construction of promising anti-biofouling biosensors and bioelectronics.


Asunto(s)
Incrustaciones Biológicas , Técnicas Biosensibles , COVID-19 , Ácidos Nucleicos , Humanos , Incrustaciones Biológicas/prevención & control , Fosforilación , Saliva , SARS-CoV-2 , Péptidos/química , Oligopéptidos , Técnicas Electroquímicas
6.
New Phytol ; 240(4): 1534-1547, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37649282

RESUMEN

Predicting and managing the structure and function of plant microbiomes requires quantitative understanding of community assembly and predictive models of spatial distributions at broad geographic scales. Here, we quantified the relative contribution of abiotic and biotic factors to the assembly of phyllosphere bacterial communities, and developed spatial distribution models for keystone bacterial taxa along a latitudinal gradient, by analyzing 16S rRNA gene sequences from 1453 leaf samples taken from 329 plant species in China. We demonstrated a latitudinal gradient in phyllosphere bacterial diversity and community composition, which was mostly explained by climate and host plant factors. We found that host-related factors were increasingly important in explaining bacterial assembly at higher latitudes while nonhost factors including abiotic environments, spatial proximity and plant neighbors were more important at lower latitudes. We further showed that local plant-bacteria associations were interconnected by hub bacteria taxa to form metacommunity-level networks, and the spatial distribution of these hub taxa was controlled by hosts and spatial factors with varying importance across latitudes. For the first time, we documented a latitude-dependent importance in the driving factors of phyllosphere bacteria assembly and distribution, serving as a baseline for predicting future changes in plant phyllosphere microbiomes under global change and human activities.


Asunto(s)
Bacterias , Microbiota , Humanos , ARN Ribosómico 16S/genética , Bacterias/genética , Plantas/genética , Hojas de la Planta/microbiología
7.
Chemistry ; 29(23): e202300209, 2023 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-36762405

RESUMEN

Stimuli-induced structural transformation of supramolecular cages has drawn increasing attention because of their sensitive feature to external variations as model systems to simulate biological processes. However, combining structural transformation and useful functions has remained a difficult task. This study reports the solvato-controlled self-assembly of two unique topologies with different emission characteristics, a water-soluble Ag8 L4 cage (A) and an Ag4 L2 cage (B), produced from the same sulfonate-pendant tetraphenylethene (TPE) bridged tetrakis-(1,2,4-triazolium) ligand. Both cages show interesting solvent-responsive reversible structural transformation, and the change of fluorescence signals can efficiently track the process. Additionally, water-soluble cage A exhibits unique properties in thermochromism, thiol amino acid sensing, and subcellular imaging in aqueous media.

8.
Proc Biol Sci ; 288(1948): 20203045, 2021 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-33849320

RESUMEN

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographical heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.


Asunto(s)
Biodiversidad , Árboles , Ecología , Asia Oriental
9.
Anal Bioanal Chem ; 413(11): 3131-3140, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33715040

RESUMEN

Simultaneous detection of patulin (PAT) and ochratoxin A (OTA) in food products is in great demand, which can prevent toxins from being exposed to human and animal bodies. However, simultaneous detection of multiple targets still faces a challenge. Herein, we developed a novel electrochemical aptasensor for the simultaneous detection of PAT and OTA in apple juice based on gold nanoparticles decorated black phosphorus (AuNPs-BP) nanomaterial. AuNPs-BP function?/work? as a sensing platform for loading much different electrochemical signal molecules functionalized aptamers. In this context, methylene blue functionalized PAT aptamers (Mb-PAT-aptamers) and ferrocene functionalized OTA aptamers (Fc-OTA-aptamers) have been introduced here to fabricate the aptasensor. Fc close to electrode surface showed a strong signal, whereas Mb was far away from electrode surface so exhibited a weak signal in the absence of OTA and PAT. Two kinds of electrochemical signal changes have been recorded dependent on target of OTA and PAT concentrations. So, simultaneous detection of OTA and PAT is achieved. Under the optimum conditions, using this developed biosensor, PAT and OTA can be quantified at a linearity range of 0.01 × 10-7 µg·mL-1 ~ 0.10 µg·mL-1. In addition, it also has good selectivity, stability and repeatability. For the practical application, it shows promising performance for the simultaneous detection of PAT and OTA in apple juice.


Asunto(s)
Técnicas Electroquímicas/métodos , Jugos de Frutas y Vegetales/análisis , Oro/química , Malus/química , Nanopartículas del Metal/química , Ocratoxinas/análisis , Patulina/análisis , Fósforo/química , Límite de Detección , Reproducibilidad de los Resultados
10.
Anal Bioanal Chem ; 413(3): 839-851, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33219832

RESUMEN

Here, we design and synthesize a novel 2D Cu-tetrakis(4-carboxyphenyl)porphyrin (TCPP) metal-organic framework (MOF) sheet and ultrasmall Cu5.4O nanoparticle (Cu5.4O USNP) hybrid (Cu-TCPP MOF/Cu5.4O nanocomposite). The graphene-like ultrathin Cu-TCPP MOF sheets offer high surface-to-volume atom ratios and many active sites, which is beneficial for loading more Cu5.4O USNPs. The Cu5.4O USNPs with ultrasmall size (<5 nm) have promising conductivity and excellent enzymatic ability for H2O2. The successfully prepared nanocomposites are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) techniques. The 2D graphene-like ultrathin Cu-TCPP MOF sheets show no H2O2-sensing signals, whereas Cu5.4O USNPs exhibit a clear reduction peak for detection of H2O2. Interestingly, the combination of two kinds of nanomaterials improved the H2O2 sensing ability due to their synergistic effect. The properties of the unmodified electrodes and the Cu-TCPP MOF/Cu5.4O nanocomposite-modified electrodes were systemically studied by cyclic voltammetry (CV), current-time (i-t) response, and square-wave voltammetry (SWV) techniques. The electrochemical sensor for the detection of H2O2 based on the Cu-TCPP MOF/Cu5.4O nanocomposite has a lower detection limit of 0.13 µmol·L-1 and wider linear range of 0.1 × 10-6 ~ 0.59 × 10-3 mol·L-1 and 1.59 × 10-3 ~ 20.59 × 10-3 mol·L-1 when compared with the Cu5.4O USNPs-modified electrode. The electrochemical sensor can be further used to detect H2O2 produced by cells. Graphical abstract The mechanism for sensing H2O2 produced from cells based on a Cu-TCPP MOF/Cu5.4O USNPs nanocomposite-modified electrode.


Asunto(s)
Cobre/química , Peróxido de Hidrógeno/análisis , Nanopartículas del Metal/química , Estructuras Metalorgánicas/química , Porfirinas/química , Límite de Detección , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Análisis Espectral/métodos , Difracción de Rayos X
11.
Ecol Lett ; 22(2): 245-255, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30548766

RESUMEN

Climate is widely recognised as an important determinant of the latitudinal diversity gradient. However, most existing studies make no distinction between direct and indirect effects of climate, which substantially hinders our understanding of how climate constrains biodiversity globally. Using data from 35 large forest plots, we test hypothesised relationships amongst climate, topography, forest structural attributes (stem abundance, tree size variation and stand basal area) and tree species richness to better understand drivers of latitudinal tree diversity patterns. Climate influences tree richness both directly, with more species in warm, moist, aseasonal climates and indirectly, with more species at higher stem abundance. These results imply direct limitation of species diversity by climatic stress and more rapid (co-)evolution and narrower niche partitioning in warm climates. They also support the idea that increased numbers of individuals associated with high primary productivity are partitioned to support a greater number of species.


Asunto(s)
Biodiversidad , Árboles , Clima
12.
Mikrochim Acta ; 186(4): 238, 2019 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-30868260

RESUMEN

An aptamer based impedimetric assay for the mycotoxin patulin (PAT) is described. A glassy carbon electrode (GCE) was modified with black phosphorus nanosheets (BP NSs) and modified with PAT aptamer by electrostatic attraction. Detection is based on the variations of electron transfer resistance at the modified electrode surface. This assay can detect PAT over a linear range that extends from 1.0 nM to 1.0 µM with a 0.3 nM detection limit. To improve the performance of the sensor, the BP NS-GCE was further modified with gold nanoparticles and then with thiolated PAT aptamer. This modified electrode, operated at an applied potential of 0.18 V (vs. Ag/AgCl), has a wider linear range (0.1 nM to 10.0 µM) and a lower detection limits (0.03 nM). Both assays were successfully applied to the analysis of (spiked) genuine food samples. Graphical abstract Black phosphorus nanosheets (BP NSs) were used to fabricate an aptamer based assay for patulin. To further improve the performance of the electrode, gold nanoparticles (AuNP) were placed on the surface of black phosphorus nanosheets (AuNP-BP NSs) by electrostatic attraction for patulin aptasensing.

13.
J Environ Manage ; 248: 109249, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31362172

RESUMEN

Cities worldwide are increasingly using green infrastructure to mitigate challenges related to stormwater, in an approach regarded as sustainable stormwater management (SSM). Various governance factors have been identified as one of the major barriers to SSM implementation. In this study, we examined specific governance factors influencing local SSM implementation in four case cities in Sweden and China. Based on systems thinking, we first developed a general causal loop diagram (SSM-CLD) illustrating the interrelations between previously identified influencing governance factors in SSM. We then used this general SSM-CLD as a framework to conduct and analyze 23 semi-structured interviews with local government officers in the four case cities. Based on the analysis, we summarized the most frequently mentioned governance factors and created one SSM-CLD for each case city. We then examined the main differences between the local SSM-CLDs and the general SSM-CLD, and the differences between the Chinese and Swedish case cities. The results revealed that, in the two Chinese case cities, the role of national policy in setting local leaders' priorities, the strong organizational set-up, and planning instruments are significant for SSM implementation. In the two Swedish case cities, public awareness, local government politicians' priorities, and trust in SSM performance are important for SSM implementation. Acquiring funding for long-term maintenance of SSM was identified as a common challenge in all four cities studied. These results provide a better understanding and potential lessons for other cities on how governance factors influence SSM.


Asunto(s)
Organizaciones , China , Ciudades , Suecia
14.
Anal Chim Acta ; 1316: 342821, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-38969423

RESUMEN

The monitoring of biomarkers in wound exudate is of great importance for wound care and treatment, and electrochemical biosensors with high sensitivity are potentially useful for this purpose. However, conventional electrochemical biosensors always suffer from severe biofouling when performed in the complex wound exudate. Herein, an antifouling electrochemical biosensor for the detection of involucrin in wound exudate was developed based on a wound dressing, oxidized bacterial cellulose (OxBC) and quaternized chitosan (QCS) composite hydrogel. The OxBC/QCS hydrogel was prepared using an in-situ chemical oxidation and physical blending method, and the proportion of OxBC and QCS was optimized to achieve electrical neutrality and enhanced hydrophilicity, therefore endowing the hydrogel with exceptional antifouling and antimicrobial properties. The involucrin antibody SY5 was covalently bound to the OxBC/QCS hydrogel to construct the biosensor, and it demonstrated a low limit of detection down to 0.45 pg mL-1 and a linear detection range from 1.0 pg mL-1 to 1.0 µg mL-1, and it was capable of detecting targets in wound exudate. Crucially, the unique antifouling and antimicrobial capability of the OxBC/QCS hydrogel not only extends its effective lifespan but also guarantees the sensing performance of the biosensor. The successful application of this wound dressing, OxBC/QCS hydrogel for involucrin detection in wound exudate demonstrates its promising potential in wound healing monitoring.


Asunto(s)
Técnicas Biosensibles , Celulosa , Quitosano , Técnicas Electroquímicas , Oxidación-Reducción , Quitosano/química , Celulosa/química , Incrustaciones Biológicas/prevención & control , Humanos , Hidrogeles/química , Exudados y Transudados/química , Límite de Detección
15.
Sci Total Environ ; 927: 172163, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38569958

RESUMEN

The early growth stage of plants is vital to community diversity and community regeneration. The Janzen-Connell hypothesis predicts that conspecific density dependence lowers the survival of conspecific seedlings by attracting specialist natural enemies, promoting the recruitment and performance of heterospecific neighbors. Recent work has underscored how this conspecific negative density dependence may be mediated by mutualists - such as how mycorrhizal fungi may mediate the accrual of host-specific pathogens beneath the crown of conspecific adult trees. Aboveground mutualist and enemy interactions exist as well, however, and may provide useful insight into density dependence that are as of yet unexplored. Using a long-term seedling demographic dataset in a subtropical forest plot in central China, we confirmed that conspecific neighborhoods had a significant negative effect on seedling survival in this subtropical forest. Furthermore, although we detected more leaf damage in species that were closely related to ants, we found that the presence of ants had significant positive effects on seedling survival. Beside this, we also found a negative effect of ant appearance on seedling growth which may reflect a trade-off between survival and growth. Overall, our findings suggested that ants and conspecific neighborhoods played important but inverse roles on seedling survival and growth. Our results suggest ants may mediate the influence of conspecific negative density dependence on seedling survival at community level.


Asunto(s)
Hormigas , Bosques , Herbivoria , Plantones , China , Animales , Plantones/fisiología , Hormigas/fisiología , Árboles/fisiología , Densidad de Población , Simbiosis
16.
Anal Chim Acta ; 1287: 342154, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38182356

RESUMEN

Wearable sweat sensors with stretch capabilities and robust performances are desired for continuous monitoring of human health, and it remains a challenge for sweat sensors to detect targets reliably in both static and dynamic states. Herein, a flexible sweat sensor was created using a cost-effective approach involving the utilization of three-dimensional graphene foam and polydimethylsiloxane (PDMS). The flexible electrochemical sensor was fabricated based on PDMS and Pt/Pd nanoparticles modified 3D graphene foam for the detection of uric acid in sweat. Pt/Pd nanoparticles were electrodeposited on the graphene foam to markedly enhance the electrocatalytic activity for uric acid detection. The graphene foam with excellent electrical property and high porosity, and PDMS with an ideal mechanical property endow the sensing device with high stretchability (tolerable strain up to 110 %), high sensitivity (0.87 µA µM-1 cm-2), and stability (remaining unchanged for more than 5000 cycles) for daily wear. To eliminate possible interferences, the wearable sensor was designed with dual working electrodes, and their response difference ensured reliable and accurate detection of targets. This strategy of constructing sweat sensors with dual working electrodes based on the flexible composite material represents a promising way for the development of robust wearable sensing devices.


Asunto(s)
Grafito , Dispositivos Electrónicos Vestibles , Humanos , Sudor , Ácido Úrico , Electrodos
17.
Ecology ; 105(9): e4380, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39031002

RESUMEN

Mutualistic symbioses between ants and plants are widespread in nature. Ants can deter unwanted pests and provide protection for plants in return for food or housing rewards. Using a long-term demographic dataset in a tropical seasonal rain forest in Southwest China, we found that associations with ants positively influenced seedling survival and adult growth, and also, species with extrafloral nectaries experienced weaker conspecific negative density dependence compared with species without extrafloral nectaries. Furthermore, we found strong evidence suggesting that species in our forest experienced conspecific density dependence, which we interpreted as heavy pest pressure that may drive the development of anti-pest symbioses such as the plant-ant relationship. Our findings suggest that ants and conspecific neighbors play important but inverse roles on plant survival and growth and that ants can buffer tree neighborhood interactions in this tropical forest.


Asunto(s)
Hormigas , Animales , China , Hormigas/fisiología , Bosques , Clima Tropical , Árboles , Simbiosis
18.
ACS Sens ; 8(7): 2834-2842, 2023 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-37470172

RESUMEN

Although continuous monitoring of constituents in complex sweat is crucial for noninvasive physiological evaluation, biofouling on the sweat sensor surface and inadequate flexible self-healing materials restrict its applications. Herein, a fully self-healing and strong anti-biofouling polypeptide complex hydrogel (AuNPs/MoS2/Pep hydrogel) with excellent electrochemical performances was created. The anti-fouling electrochemical sweat sensor was fabricated based on the AuNPs/MoS2/Pep hydrogel to address these issues. It was found that the polypeptide hydrogel was designed to form a network structure and carried abundant hydrophilic groups, resulting in a AuNPs/MoS2/Pep hydrogel with superior anti-biofouling properties in sweat for 30 min and even long-term stability in undiluted human sweat. In addition, SEM, TEM, UV, XPS, and infrared spectrogram demonstrated that the binding force of π-π stacking force between MoS2 and naphthalene groups in the designed peptide endowed the polypeptide complex hydrogel with an excellent self-healing property. Furthermore, the polypeptide complex hydrogel preserved wearable device function of continuously monitoring uric acid (UA) and ascorbic acid (AA) in sweat in situ. This novel fabricated sweat sensor with high anti-biofouling ability, excellent self-healing property, and sensitive and selective analytical capability describes a new opportunity for health monitoring in situ.


Asunto(s)
Incrustaciones Biológicas , Nanopartículas del Metal , Dispositivos Electrónicos Vestibles , Humanos , Sudor/química , Hidrogeles/química , Incrustaciones Biológicas/prevención & control , Oro/análisis , Molibdeno
19.
Biosens Bioelectron ; 225: 115101, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36708624

RESUMEN

The electrochemical biosensor with outstanding sensitivity and low cost is regarded as a viable alternative to current clinical diagnostic techniques for various disease biomarkers. However, their actual analytical use in complex biological samples is severely hampered due to the biofouling, as they are also highly sensitive to nonspecific adsorption on the sensing interfaces. Herein, we have constructed a non-fouling electrochemical biosensor based on antifouling peptides and the electroneutral peptide nucleic acid (PNA), which was used as the recognizing probe for the specific binding of the viral RNA of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Different from the negatively charged DNA probes that will normally weaken the biosensors' antifouling capabilities owing to the charge attraction of positively charged biomolecules, the neutral PNA probe will generate no side-effects on the biosensor. The biosensor demonstrated remarkable sensitivity in detecting SARS-CoV-2 viral RNA, possessing a broad linear range (1.0 fM - 1.0 nM) and a detection limit down to 0.38 fM. Furthermore, the sensing performance of the constructed electrochemical biosensor in human saliva was nearly similar to that in pure buffer, indicating satisfying antifouling capability. The combination of PNA probes with antifouling peptides offered a new strategy for the development of non-fouling sensing systems capable of assaying trace disease biomarkers in complicated biological media.


Asunto(s)
Incrustaciones Biológicas , Técnicas Biosensibles , COVID-19 , Ácidos Nucleicos , Ácidos Nucleicos de Péptidos , Humanos , Ácidos Nucleicos de Péptidos/química , Incrustaciones Biológicas/prevención & control , Saliva , Técnicas Biosensibles/métodos , COVID-19/diagnóstico , Técnicas Electroquímicas/métodos , SARS-CoV-2 , Péptidos/química , Biomarcadores
20.
Anal Chim Acta ; 1283: 341948, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37977778

RESUMEN

The challenge of heavy biofouling in complex sweat environments limits the potential of electrochemical sweat sensors for noninvasive physiological assessment. In this study, a novel semi-interpenetrating hydrogel of PSBMA/PEDOT:PSS was engineered by interlacing PEDOT:PSS conductive polymer with zwitterionic PSBMA network. This versatile hydrogel served as the foundation for developing an anti-fouling wearable molecular imprinting sensor capable of sensitive and robust detection of tryptophan (Trp) in complex sweat. The incorporation of PEDOT:PSS conductive polymer into the semi-interpenetrating hydrogel introduced diverse physical crosslinks, including hydrogen bonding, electrostatic interactions, and chain entanglement. This incorporation considerably boosted the hydrogel's mechanical robustness and imparted commendable self-healing property. At the same time, the synergistic coupling between the well-balanced charge of the zwitterionic network and the high conductivity of the PEDOT:PSS polymer facilitated efficient charge transfer. The formation of the desired molecular imprinting membrane of semi-interpenetrating hydrogel was triggered by self-polymerization of dopamine (DA) in the presence of Trp. The designed biosensor demonstrated good sensitivity, selectivity and stability in detecting the target Trp. Notably, it also exhibited exceptional anti-fouling abilities, allowing for accurate Trp detection in complex real sweat samples, yielding results comparable to commercial enzyme-linked immunoassay (ELISA).


Asunto(s)
Incrustaciones Biológicas , Impresión Molecular , Dispositivos Electrónicos Vestibles , Hidrogeles/química , Sudor/química , Incrustaciones Biológicas/prevención & control , Triptófano/análisis , Polímeros/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA