Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 278
Filtrar
1.
Environ Sci Technol ; 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33190494

RESUMO

This study explored the possibility of incorporating extremophilic algal cultivation into dairy wastewater treatment by characterizing a unique algal strain. Results showed that extremophilic microalgae Chlorella vulgaris CA1 newly isolated from dairy wastewater tolerated a high level of ammonia nitrogen (2.7 g/L), which was over 20 times the ammonia nitrogen that regular Chlorella sp. could tolerate. The isolate was mixotrophically cultured in dairy effluent treated by anaerobic digestion (AD) for recycling nutrients and polishing the wastewater. The highest biomass content of 13.3 g/L and protein content of 43.4% were achieved in the culture in AD effluent. Up to 96% of the total nitrogen and 79% of the total phosphorus were removed from the dairy AD effluent. The ability of the algae to tolerate a high level of ammonia nitrogen suggests the potential for direct nutrient recycling from dairy wastewater while producing algal biomass and high value bioproducts.

2.
J Fish Dis ; 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33103274

RESUMO

Water temperature has a major influence on the host innate immune defence and the infectivity of pathogens in ectothermic teleosts. Toll-like receptors (TLRs) are the first and well-characterized innate immune receptors that are conserved in vertebrates. However, little is known about the effect of temperature variation on TLRs in fish species. In this study, we used adult zebrafish as a research model to investigate the effect of water temperature on TLRs. Whole genome searches identified 20 TLR homologue genes in zebrafish. Multiple sequence alignment and protein structure analysis revealed the conserved domains for these TLR proteins. To identify TLR genes related to temperature variation, TLR family genes from 12 species with different body temperatures were assigned to conduct phylogenetic analyses. Based on the phylogenetic relationships, TLR3, TLR4, TLR5 and TLR20~21 were selected as candidate genes. Immunostimulation data indicated that TLR3, TLR5, and TLR21 were more sensitive to temperature variation and their expression levels were affected in response to pathogen stimulation. Taken together, our results provide a new opportunity to understand the roles of temperature on host innate immune response in fishes and have broader implications for disease prevention in aquaculture.

3.
Cancer Control ; 27(1): 1073274820954458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32959672

RESUMO

INTRODUCTION: Using the TMN classification alone to predict survival in patients with gastric cancer has certain limitations, we conducted this study was to develop an effective nomogram based on aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio to predict overall survival (OS) in surgically treated gastric cancer. METHODS: we retrospectively analyzed 190 cases of gastric cancer and used Cox regression analysis to identify the significant prognostic factors for OS in patients with resectable gastric cancer. The predictive accuracy of nomogram was assessed using a calibration plot, concordance index (C-index) and decision curve. This was then compared with a traditional TNM staging system. Based on the total points (TPS) by nomogram, we further divided patients into different risk groups. RESULTS: multivariate analysis of the entire cohort revealed that independent risk factors for survival were age, clinical stage and AST/ALT ratio, which were entered then into the nomogram. The calibration curve for the probability of OS showed that the nomogram-based predictions were in good agreement with actual observations. Additionally, the C-index of the established nomogram for predicting OS had a superior discrimination power compared to the TNM staging system [0.794 (95% CI: 0.749-0.839) vs 0.730 (95% CI: 0.688-0.772), p < 0.05]. Decision curve also demonstrated that the nomogram was better than the TNM staging system. Based on TPS of the nomogram, we further subdivided the study cohort into 3 groups including low risk (TPS ≤ 158), middle risk (158 < TPS ≤ 188) and high risk (TPS > 188) categories. The differences in OS rate were significant among the groups. CONCLUSION: the established nomogram is associated with a more accurate prognostic prediction for individual patients with resectable gastric cancer.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32924425

RESUMO

Iron pyrite (FeS2) is a promising lithium-ion battery cathode material because of its low cost and ultrahigh energy density (1671 Wh kg-1). However, its reaction mechanisms are still controversial. In this work, we find that different from the conventional belief that an intermediate phase Li2FeS2 is formed followed by Fe/Li2S composites at the initial discharge, it undergoes a one-step reaction (FeS2 → Fe + Li2S) or a two-step reaction (FeS2 → FeS + Li2S → Fe + Li2S), which depends on the current rate and temperature. In the charge process, it undergoes a two-step reaction: phase transition Fe + Li2S → FeS at about 1.74 V and generation of elemental sulfur (Li2S → S, 2.30 V). FeS is a mackinawite phase that is formed on the interface of Li2S via heteroepitaxial growth. Subsequent cycles involves a combination reaction of FeS and S. The reaction mechanism suggests that FeS2 suffers from the demerits of both FeS and S, such as a large volume change, voltage hysteresis, and polysulfide dissolution. These findings would help us to understand the intrinsic capacity fading of FeS2 and provide guidelines to improve its electrochemical performances.

5.
Adv Healthc Mater ; : e2000722, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32989913

RESUMO

Eccrine sweat contains a rich blend of electrolytes, metabolites, proteins, metal ions, and other biomarkers. Changes in the concentrations of these chemical species can indicate alterations in hydration status and they can also reflect health conditions such as cystic fibrosis, schizophrenia, and depression. Recent advances in soft, skin-interfaced microfluidic systems enable real-time measurement of local sweat loss and sweat biomarker concentrations, with a wide range of applications in healthcare. Uses in certain contexts involve, however, physical impacts on the body that can dynamically deform these platforms, with adverse effects on measurement reliability. The work presented here overcomes this limitation through the use of microfluidic structures constructed in relatively high modulus polymers, and designed in geometries that offer soft, system level mechanics when embedded low modulus elastomers. Analytical models and finite element analysis quantitatively define the relevant mechanics of these systems, and serve as the basis for layouts optimized to allow robust operation in demanding, rugged scenarios such as those encountered in football, while preserving mechanical stretchability for comfortable, water-tight bonding to the skin. Benchtop testing and on-body field studies of measurements of sweat loss and chloride concentration under imposed mechanical stresses and impacts demonstrate the key features of these platforms.

6.
Nano Lett ; 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32786951

RESUMO

Lead halide perovskites have emerged as excellent optical gain materials for solution-processable and flexible lasers. Recently, continuous-wave (CW) optically driven lasing was established in perovskite crystals; however, the mechanism of low-threshold operation is still disputed. In this study, CW-pumped lasing from one-dimensional CsPbBr3 nanoribbons (NBs) with a threshold of ∼130 W cm-2 is demonstrated, which can be ascribed to the large refractive index induced by the exciton-polariton (EP) effect. Increasing the temperature reduces the exciton fraction of EPs, which decreases the group and phase refractive indices and inhibits lasing above 100 K. Thermal management, including reducing the NB height to ∼120 ± 60 nm and adopting a high-thermal-conductivity sink, e.g., sapphire, is critical for CW-driven lasing, even at cryogenic temperatures. These results reveal the nature of ultralow-threshold lasing with CsPbBr3 and provide insights into the construction of room-temperature CW and electrically driven perovskite macro/microlasers.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32667181

RESUMO

Two-dimensional transition-metal dichalcogenides hold great potential in rechargeable lithium ion batteries. Their electrochemical properties are closely related to the structural evolutions during lithium ion migration. Understanding these migration/reaction mechanisms is important to help improve battery performance. Herein, we report the real-time and atomic-scale observation of phase transitions during the lithiation and delithiation for V5S8 via in situ electron diffraction and high-resolution transmission electron microscopy techniques. We find that the phase transformation proceeds via a sequence of order to antisite disorder intercalation and topotactic-based conversion reaction. During the intercalation reaction, the lithium ion destroys the orderings of the interstitial V with the formation of Li/V antisite. Such a reaction is found to be reversible, i.e., the extraction of the lithium from LixV5S8 leads to the recovery of V orderings. The conversion reaction involves heterogeneous nucleation of the Li2S with 3-20 nm nanodomains, which maintain the crystallographic integrity with LixV5S8. These findings elucidate the complex interactions between lithium ion and host V5S8 during ionic migration in the solids, which should be helpful in understanding the relationship between phase transformation kinetics and battery performance.

8.
Biol Res ; 53(1): 32, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32727578

RESUMO

BACKGROUND: Circulating RNA (circRNA) regulates various bioactivities in cells. A better understanding of the exosomal circRNA can provide novel insights into the pathogenesis and treatment of Graves' disease (GD). We aimed to profile the differentially expressed circRNAs (DEcRs) in plasma exosomes of patients with GD and speculate and probe the functions of the DEcR by comprehensive bioinformatics analyses. METHODS: Serum exosomes were isolated from five primary GD patients and five healthy controls via ultracentrifugation. After verification with transmission electron microscopy, exosome samples were subjected to microarray profiling using human circRNA microarrays. Two up-regulated and two down-regulated DEcRs were selected for validation in plasma exosomes from 20 GD and 20 healthy control participants using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). The circRNA/microRNA/mRNA interaction network was then assembled and the analysis of the Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways was utilized to predict the potential functions of the DEcR associated genes. RESULTS: There were 15 DEcRs revealed in primary GD cases. The intronic circRNA hsa_circRNA_000102 was confirmed as an up-regulated component in plasma exosomes from patients with GD. The circRNA/microRNA/mRNA interaction network unveiled the most potential targeting microRNAs of hsa_circRNA_000102 and its associated genes. The functional analyses predicted involvement of hsa_circRNA_000102 associated genes in pathways of immune system activation, such as viral infection and interferon-beta signaling. CONCLUSIONS: hsa_circRNA_000102 is a differentially up-regulated plasma exosomal circRNA in patients with GD. Our study highlights multiple pathways, particularly virus infection and interferon-beta signaling, for mediating immune activation in Graves' disease.


Assuntos
Doença de Graves/sangue , Doença de Graves/genética , Análise em Microsséries , RNA Circular/sangue , Exossomos , Feminino , Humanos , Masculino , MicroRNAs , RNA Mensageiro
9.
Health Qual Life Outcomes ; 18(1): 242, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32690060

RESUMO

BACKGROUND: It is not well clear how psychosocial factors like depressive symptoms, social support affect quality of life in rural elderly in China. This study aimed to investigate the mediating role of depressive symptoms in the association between social support and quality of life. METHODS: Cross-sectional data of 420 rural elderly were taken from four villages in Hangzhou City. They were interviewed with a demographic questionnaire, the Patient Health Questionnaire (PHQ-9) for depression, the Medical Outcomes Study Social Support Survey (MOS-SSS) for social support, and the short version of World Health Organization Quality of Life Assessment (WHOQOL-BREF) for quality of life. Mediation was examined by a nonparametric Bootstrapping method, controlling for socioeconomic variables. RESULTS: Poor quality of life was associated with low social support and increased depressive symptoms. A significant indirect effect of social support existed through depression in relation to quality of life (ab = 0.0213, 95% CI [0.0071, 0.0421]), accounting for 9.5% of the effect of social support on quality of life. Approximately 4.8% of the variance in QOL was attributable to the indirect effect of social support through depressive symptoms. CONCLUSIONS: Depressive symptoms mediated the impact of social support on quality of life among rural older adults.


Assuntos
Depressão/psicologia , Qualidade de Vida , Apoio Social , Inquéritos e Questionários/normas , Idoso , Idoso de 80 Anos ou mais , China , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , População Rural/estatística & dados numéricos , Organização Mundial da Saúde
11.
ACS Synth Biol ; 9(8): 2208-2213, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32584553

RESUMO

Promoters are critical tools to precisely control gene expression for both synthetic biology and metabolic engineering. Although Yarrowia lipolytica has demonstrated many industrially relevant advantages, promoter discovery efforts on this non-conventional yeast are limited due to the challenge in finding suitable inducible and repressible promoters. Six copper-inducible promoters and five repressible promoters were isolated in this work. Especially, Cu2+-repressible promoters showed relatively high activity under non-repressing conditions compared with a constitutive promoter, but the strength could be almost fully repressed by a supplement of a low content of Cu2+. The six Cu2+-inducible promoters were engineered to improve their dynamic regulation range with a tandem upstream activation sequence. An engineered promoter was successfully used to construct a more productive pathway for production of a novel bioproduct, wax ester, than that used for both Cu2+-inducible promoter and constitutive promoter. This study provides effective tools applicable to fine-tune the gene expression in this microbial host.

12.
Adv Mater ; : e2001107, 2020 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-32419179

RESUMO

Organic-inorganic hybrid perovskites (OIHPs) have generated considerable excitement due to their promising photovoltaic performance. However, the commercialization of perovskite solar cells (PSCs) is still plagued by the structural degradation of the OIHPs. Here, the decomposition mechanism of OIHPs under electron beam irradiation is investigated via transmission electron microscopy, and a general decomposition pathway for both tetragonal CH3 NH3 PbI3 and cubic CH3 NH3 PbBr3 is uncovered through an intermediate superstructure state of CH3 NH3 PbX2.5 , X = I, Br, with ordered vacancies into final lead halides. Such decomposition can be suppressed via carbon coating by stabilization of the perovskite structure framework. These findings reveal the general degradation pathway of OIHPs and suggest an effective strategy to suppress it, and the atomistic insight learnt may be useful for improving the stability of PSCs.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32363851

RESUMO

The patterning of silver nanowires (AgNWs) is subject to critical challenges, which have seriously limited their practical applications. This work describes a simple and efficient method combining screen printing with vacuum filtration for patterning AgNW networks. The screen-printed poly(dimethylsiloxane) (PDMS) mask layer was shown to be strongly adhered to the filtration membrane, which resulted in well-defined sharp edges of the deposited AgNW patterns, and a 50 µm patterning resolution was achieved. The patterned films with low densities of AgNWs (≤15 µg/cm2) were transferred to the surface of PDMS to make patterned stretchable transparent conductive films (TCFs). The low sheet resistance of 7.3 Ω/sq was achieved at an optical transmittance of 79.6% (at 550 nm wavelength) with a AgNW deposition density of only 12.5 µg/cm2. As an application example, the patterned TCFs were used as the top electrodes to fabricate stretchable alternating current electroluminescent (ACEL) displays with stretchability up to 70% of their original dimension, which were applied to a smart system for simulating heart beats together with a digitally operated flexible circuit. The ACEL device exhibited a bright and uniform emission with a clear and smooth edge even with a pattern width as narrow as 100 µm, as well as exceptional elasticity and durability in spite of bending, stretching, and twisting. The present work provides a new way of patterning AgNWs and can be extended to a variety of applications.

14.
Fish Shellfish Immunol ; 101: 88-98, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32229294

RESUMO

Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) are a family of crucial signaling molecules that mediate the signal transduction of various immune signaling pathways. Extensive studies have demonstrated that TRAFs play vital roles in regulating cellular immune responses. However, the biological functions and expression profiling of TRAFs in Chinese soft-shelled turtle (Pelodiscus sinensis) remain unclear. In this study, the genes of the PsTRAF family at the genome-wide level were identified in P. sinensis, revealing six PsTRAF members that contained the conserved TRAF domain in the C-terminal regions. Molecular evolutionary analysis showed that PsTRAFs shared close evolutionary relationships and similar protein crystal structures with the TRAF homologs from other turtles, indicating the evolutionary conservation of PsTRAFs. Further expression analysis revealed the tissue-specific expression of PsTRAF genes. Obvious variations in the expression of PsTRAF genes were observed in the spleen in response to Aeromonas hydrophila infection. Three PsTRAF genes, PsTRAF2, PsTRAF3, and PsTRAF6, were significantly upregulated at the mRNA and protein levels post-infection, indicating their potential function in the immune response. Moreover, the protein-protein associations of PsTRAFs with several signaling receptors were predicted in P. sinensis. These results provide a basis for the investigation of the functional roles of PsTRAFs in immune defense against bacterial infection.

15.
Nano Lett ; 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32096644

RESUMO

At the mesoscopic level of commercial lithium ion battery (LIB), it is widely believed that the poor contacts between current collector (CC) and electrode materials (EM) lead to weak adhesions and large interfacial electric resistances. However, systematic quantitative analyses of the influence of the interfacial properties of CC are still scarce. Here, we built a model interface between CC and electrode materials by directly growing hierarchical graphene films on commercial Al foil CC, and we performed systematic quantitative studies of the interfacial properties therein. Our results show that the interfacial electric resistance dominates, i.e. ∼2 orders of magnitude higher than that of electrode materials. The interfacial resistance could be eliminated by hierarchical graphene interlayer. Cathode on CC with eliminated interfacial resistance could deliver much improved power density outputs. Our work quantifies the mesoscopic factors influencing the battery performance and offers practical guidelines of boosting the performance of LIBs and beyond.

16.
Enzyme Microb Technol ; 134: 109487, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32044034

RESUMO

Haematococcus pluvialis could accumulate large amounts of triacylglycerol (TAG) and astaxanthin under various environmental stresses. To gain insights into the multiple defensive systems for carbon metabolism against nitrogen starvation, transcriptome analysis was performed. It was found that the genes related to carbon fixation, glycolysis, fatty acid and carotenoid biosynthesis pathways were up-regulated remarkably. Glyceraldehyde 3-phosphate (G3P) biosynthesis was accelerated with the enhanced C3 and C4 pathway. Meanwhile, the pyruvate kinase (PK) and pyruvate dehydrogenase E2 component (aceF) genes were significantly increased 12.9-fold and 13.9-fold, respectively, resulting more pyruvate and acetyl-CoA generation, which were beneficial to carotenoids and fatty acid biosynthesis. Methylerythritol 4-phosphate (MEP) pathway mediated carotenoid precursor isopentenyl diphosphate (IPP) synthesis, as the all eight related genes were up-regulated. The carbon flux toward astaxanthin biosynthesis with the increased astaxanthin pathway genes. The redistribution of carbon was also promoted for TAG accumulation. In addition, the up-regulation of diacylglycerol acyltransferase (DGAT) and phospholipid: diacylglycerol acyltransferase (PDAT) genes indicated that both acyl-CoA dependent and independent pathway regulated TAG accumulation. Therefore, this work reveals the multiple defensive mechanism for carbon metabolism in response to nitrogen starvation, which extended our understanding on the carotenoids, TAG and other important metabolites synthesis.


Assuntos
Vias Biossintéticas/genética , Clorófitas/genética , Clorófitas/metabolismo , Perfilação da Expressão Gênica , Nitrogênio/metabolismo , Ciclo do Carbono , Carotenoides/metabolismo , Ácidos Graxos/biossíntese , Glicólise , Regulação para Cima
17.
Bioresour Technol ; 300: 122649, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896045

RESUMO

Most natural astaxanthin is fatty acid-esterified in microalgae to prevent oxidation. However, the factors influencing astaxanthin esterification (AE) are poorly understood. In this study, obstacles to AE in Coelastrum sp. HA-1 were investigated. Only half of the astaxanthin molecules in HA-1 were esterified, but AE was stimulated with exogenous linoleic acid (LA) and ethanol treatment. Astaxanthin esters and total astaxanthin (TA) with exogenous LA were elevated to 3.82-fold and 2.18-fold of control levels, respectively. Treatment with 3% (v/v) ethanol enhanced transcription of the Δ12 fatty acid desaturase gene, which caused more oleic acid (OA) to be converted to LA. Furthermore, the contents of astaxanthin esters and TA were 2.42-fold and 1.61-fold control levels, respectively. These findings confirmed that AE was upregulated by increasing LA content. Thus, a large concentration of OA alone does not increase astaxanthin accumulation in HA-1, and a certain amount of LA was necessary for AE.


Assuntos
Ácido Linoleico , Xantofilas , Esterificação , Ácidos Graxos
18.
EBioMedicine ; 51: 102566, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31901863

RESUMO

BACKGROUND: Early detection would improve upper gastrointestinal cancer prognosis. We aimed to identify serum protein biomarker for the detection of early-stage upper gastrointestinal cancer. METHODS: We performed a three-tiered study including 2028 participants from three medical centres. First, we applied two different antibody arrays to screen candidate serum proteins that increased in 20 patients with oesophageal squamous cell carcinoma (ESCC) compared with 20 normal controls. We then evaluated the selected protein by enzyme-linked immunosorbent assay in 1064 participants including 731 upper gastrointestinal cancer patients (287 ESCCs, 237 oesophagogastric junction adenocarcinomas (EJAs), and 207 stomach cancers) and 333 normal controls. The diagnostic value of the selected protein was finally validated in two independent cohorts of ESCC patients and controls (n=472 and 452, respectively). The receiver operating characteristic was used to calculate diagnostic accuracy. FINDINGS: Serum insulin-like growth factor binding protein-1 (IGFBP-1) identified in both antibody arrays showed significantly elevated levels in upper gastrointestinal cancers, compared with normal controls. Serum IGFBP-1 provided high diagnostic accuracy of early-stage ESCC, EJA, stomach and cancer (areas under the curve: 0·898, 0·936 and 0·864, respectively). This protein maintained diagnostic performance for early-stage ESCC in independent cohorts 1 and 2 (0·849 and 0·911, respectively). Additionally, serum levels of IGFBP-1 dropped significantly after surgical resection of primary tumours, compared with the corresponding pre-operative ESCC samples (p < 0·05). INTERPRETATION: Serum IGFBP-1 represents a promising diagnostic biomarker to detect early-stage upper gastrointestinal cancer.


Assuntos
Biomarcadores Tumorais/sangue , Detecção Precoce de Câncer , Carcinoma de Células Escamosas do Esôfago/sangue , Carcinoma de Células Escamosas do Esôfago/diagnóstico , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Anticorpos Antineoplásicos/imunologia , Carcinoma de Células Escamosas do Esôfago/imunologia , Carcinoma de Células Escamosas do Esôfago/patologia , Humanos , Estadiamento de Neoplasias , Curva ROC , Reprodutibilidade dos Testes
19.
Lab Chip ; 20(1): 84-92, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31776526

RESUMO

Eccrine sweat is a rich and largely unexplored biofluid that contains a range of important biomarkers, from electrolytes, metabolites, micronutrients and hormones to exogenous agents, each of which can change in concentration with diet, stress level, hydration status and physiologic or metabolic state. Traditionally, clinicians and researchers have used absorbent pads and benchtop analyzers to collect and analyze the biochemical constituents of sweat in controlled, laboratory settings. Recently reported wearable microfluidic and electrochemical sensing devices represent significant advances in this context, with capabilities for rapid, in situ evaluations, in many cases with improved repeatability and accuracy. A limitation is that assays performed in these platforms offer limited control of reaction kinetics and mixing of different reagents and samples. Here, we present a multi-layered microfluidic device platform with designs that eliminate these constraints, to enable integrated enzymatic assays with demonstrations of in situ analysis of the concentrations of ammonia and ethanol in microliter volumes of sweat. Careful characterization of the reaction kinetics and their optimization using statistical techniques yield robust analysis protocols. Human subject studies with sweat initiated by warm-water bathing highlight the operational features of these systems.

20.
Angew Chem Int Ed Engl ; 59(1): 232-236, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31609053

RESUMO

Traditional methods for analyzing organophosphorus pesticide chlorpyrifos, usually require the tedious sample pretreatment and sophisticated bio-interfaces, leading to the difficulty for real-time analysis. Herein, we use palladium single-atom (PdSA)/TiO2 as a photocatalytic sensing platform to directly detect chlorpyrifos with high sensitivity and selectivity. PdSA/TiO2 , prepared by an in situ photocatalytic reduction of PdCl4 2- on the TiO2 , shows much higher photocatalytic activity (10 mol g-1 h-1 ) for hydrogen evolution reaction than Pd nanoparticles (1.95 mol g-1 h-1 ), and excellent stability. In the presence of chlorpyrifos, the photocatalytic activity of PdSA/TiO2 decreases. Through this inhibition effect the platform can realize a detection limit for chlorpyrifos of 0.01 ng mL-1 , much lower than the maximum residue limit (10 ppb) permitted by the U.S. Environmental Protection Agency.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA