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1.
Anal Chem ; 96(21): 8365-8372, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38717986

RESUMO

Simultaneous sensitive and precise determination of multibiomarkers is of great significance for improving detection efficiency, reducing diagnosis and treatment expenses, and elevating survival rates. However, the development of simple and portable biosensors for simultaneous determination of multiplexed targets in biological fluids still faces challenges. Herein, a unique and versatile immobilization-free dual-target electrochemical biosensing platform, which combines distinguishable magnetic signal reporters with buoyancy-magnetism separation, was designed and constructed for simultaneous detection of carcinoembryonic (CEA) and α-fetoprotein (AFP) in intricate biological fluids. To construct such distinguishable magnetic signal reporters with signal transduction, amplification, and output, secondary antibodies of CEA and AFP were respectively functionalized on methylene blue (MB) and 6-(ferrocenyl)hexanethiol (FeC) modified Fe3O4@Au magnetic nanocomposites. Meanwhile, a multifunctional flotation probe with dual target recognition, capture, and isolation capability was prepared by conjugating primary antibodies (Ab1-CEA, Ab1-AFP) to hollow buoyant microspheres. The target antigens of CEA and AFP can trigger a flotation-mediated sandwich-type immunoreaction and capture a certain amount of the distinguishable magnetic signal reporter, which enables the conversion of the target CEA and AFP quantities to the signal of the potential-resolved MB and FeC. Thus, the MB and FeC currents of magnetically adsorbed distinguishable magnetic reporters can be used to determine the CEA and AFP targets simultaneously and precisely. Accordingly, the proposed strategy exhibited a delightful linear response for CEA and AFP in the range of 100 fg·mL-1-100 ng·mL-1 with detection limits of 33.34 and 17.02 fg·mL-1 (S/N = 3), respectively. Meanwhile, no significant nonspecific adsorption and cross-talk were observed. The biosensing platform has shown satisfactory performance in the determination of real clinical samples. More importantly, the proposed approach can be conveniently extended to universal detection just by simply substituting biorecognition events. Thus, this work opens up a new promising perspective for dual and even multiple targets and offers promising potential applications in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , Antígeno Carcinoembrionário , Técnicas Eletroquímicas , alfa-Fetoproteínas , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/imunologia , Antígeno Carcinoembrionário/análise , Antígeno Carcinoembrionário/imunologia , Técnicas Biossensoriais/métodos , Humanos , Imunoensaio/métodos , Ouro/química , Limite de Detecção
2.
Analyst ; 149(3): 917-924, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38190154

RESUMO

Dopamine (DA) is an important biomarker related to parkinsonism, schizophrenia and renal disease. Traditional electrochemical sensors for DA were based on the direct electrochemical oxidation of DA. In this paper, we report a new sensing strategy using N,N'-di(trimethylaminoethyl)perylene diimide (TMPDI) as an electrochemical probe and K2S2O8 as a signal enhancer for DA detection between 0 and -0.7 V with the DPV technique. MoS2 nanoflowers prepared by the hydrothermal method were used as a nanocarrier to load TMPDI. The reduction current of TMPDI was found to show a stepwise and significant increase at -0.24 V with the increase of concentration of K2S2O8 due to the continuous cycle of TMPDI molecules' electrochemical reduction and chemical oxidation. The presence of DA caused a large decrease of the reduction current of TMPDI due to the synergistic interaction of the competitive consumption of DA for K2S2O8 and the blocking effect of polyDA adhering to the electrode surface. The decreased current exhibited a linear response for DA from 10 pM to 100 µM with a detection limit of 4.1 pM and the proposed sensor showed high selectivity and excellent feasibility in human urine/serum sample detection.


Assuntos
Técnicas Eletroquímicas , Imidas , Perileno , Humanos , Técnicas Eletroquímicas/métodos , Dopamina , Oxirredução , Eletrodos , Limite de Detecção
3.
BMC Public Health ; 24(1): 1623, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890592

RESUMO

BACKGROUND: The rapid development of the telecommunications industry in the post-COVID-19 era has brought tremendous pressure to employees making them a high-risk group for job burnout. However, prior research paid less attention to the burnout of employees. Furthermore, social support and gender have separate effects on job burnout. This study explores the mechanism of stress perception on job burnout and examines the roles of social support and gender amid it. METHOD: This cross-sectional study was conducted from June 2023 to August 2023 in mainland China. A total of 39,507 were recruited by random sampling and online questionnaires, and 28,204 valid questionnaires were retained. SPSS (version 26.0) and PROCESS (Model 4 & 7) were used for correlation analysis, mediation analysis, and mediated moderation analysis. RESULT: Stress perception can positively predict the level of job burnout of employees in the telecommunications industry, and social support plays a partial mediating role, accounts for 8.01% of the total effect, gender moderates the first half of the path in this mediation model. At the same pressure level, female can perceive more social support than male. CONCLUSIONS: Under high pressure background, employees' job burnout varies depending on gender and the perception of social support. Therefore, telecommunications industry managers should adopt decompression measures and targeted social support resources for different groups.


Assuntos
Esgotamento Profissional , Apoio Social , Humanos , Masculino , Feminino , Esgotamento Profissional/psicologia , Estudos Transversais , Adulto , China/epidemiologia , Pessoa de Meia-Idade , Telecomunicações , Inquéritos e Questionários , Fatores Sexuais , Análise de Mediação , Estresse Ocupacional/psicologia , COVID-19/psicologia , COVID-19/epidemiologia
4.
Mikrochim Acta ; 191(7): 407, 2024 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898338

RESUMO

A smartphone-based electrochemical aptasensing platform was developed for the point-of-care testing (POCT) of carcinoembryonic antigen (CEA) based on the ferrocene (Fc) and PdPt@PCN-224 dual-signal labeled strategy. The prepared PdPt@PCN-224 nanocomposite showed a strong catalytic property for the reduction of H2O2. Phosphate group-labeled aptamer could capture PdPt@PCN-224 by Zr-O-P bonds to form PdPt@PCN-224-P-Apt. Therefore, a dual signal labeled probe was formed by the hybridization between Fc-DNA and PdPt@PCN-224-P-Apt. The presence of CEA forced PdPt@PCN-224-P-Apt to leave the electrode surface due to the specific affinity, leading to the decrease of the reduction current of H2O2. At the same time, the Fc-DNA strand changed to hairpin structure, which made Fc closer to the electrode and resulted in the increase of the oxidation current of Fc. Thus, CEA can be accurately determined through both signals: the decrease of H2O2 reduction current and the increase of Fc oxidation current, which could avoid the false positive signal. Under the optimal conditions, the prepared aptasensor exhibited a wide linear range from 1 pg·mL-1 to 100 ng·mL-1 and low detection limits of 0.98 pg·mL-1 and 0.27 pg·mL-1 with Fc and PdPt@PCN-224 as signal labels, respectively. The aptasensor developed in this study has successfully demonstrated its capability to detect CEA in real human serum samples. These findings suggest that the proposed sensing platform will hold great potential for clinical tumor diagnosis and monitoring.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Antígeno Carcinoembrionário , Técnicas Eletroquímicas , Compostos Ferrosos , Peróxido de Hidrogênio , Limite de Detecção , Paládio , Testes Imediatos , Smartphone , Antígeno Carcinoembrionário/sangue , Antígeno Carcinoembrionário/análise , Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Humanos , Técnicas Biossensoriais/métodos , Peróxido de Hidrogênio/química , Paládio/química , Compostos Ferrosos/química , Metalocenos/química , Platina/química
5.
Anal Chem ; 95(18): 7336-7343, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37129510

RESUMO

Rapid and accurate detection of biomolecules is of vital importance for the diagnosis of disease and for performing timely treatments. The point-of-care analysis of cancer biomarkers in the blood with low cost and easy processing is still challenging. Herein, an advanced and robust strategy, which integrates the buoyant recognition probe with the magnetic reporter probe in one solution, was first proposed for immobilization-free electrochemical immunosensing. The tumor marker of alpha fetoprotein (AFP) can be captured immune-buoyantly, and then a multifunctional magnetic reporter probe in pseudo-homogeneous solution was further captured to fulfill a sandwich-type immunoreaction. The residual magnetic reporter probe can be firmly and efficiently attracted on a magnetic glassy carbon electrode to fulfill the conversion of the target AFP amount into the residual magnetic electrochemical signal indicator. As a result, the electrochemical signal of methylene blue can accurately reflect the original level of target antigen AFP concentration. By integrating buoyancy-driven quasi-homogenous biorecognition with magnetism-mediated amplification and signal output, the proposed immobilization-free electrochemical immunosensing strategy displayed a wide range of linear response (100 fg mL-1 to 10 ng mL-1), low detection limit (14.52 fg mL-1), and good reproducibility, selectivity, and stability. The designed strategy manifests remarkable advantages including assay simplicity, rapidness, and high sensitivity owing to the in-solution instead of on-electrode biorecognition that could accelerate and improve the biorecognition efficiency. To the best of our knowledge, this is the first cooperation of buoyancy-driven biorecognition with magnetism-mediated signal output in bioanalysis, which would be attractive for rapid clinic biomedical application. Thus, this work provides a fresh perspective for convenient and favorable immobilization-free electrochemical biosensing of universal biomolecules.


Assuntos
Técnicas Biossensoriais , alfa-Fetoproteínas , alfa-Fetoproteínas/análise , Técnicas Eletroquímicas , Reprodutibilidade dos Testes , Biomarcadores Tumorais/análise , Limite de Detecção , Imunoensaio , Ouro/química
6.
Virol J ; 20(1): 209, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37684638

RESUMO

BACKGROUND: The coronavirus disease 2019 outbreak has hit Beijing since mid-Nov, 2022, with soaring growth of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children. Therefore, it is vital to determine the clinical manifestations of epidemic SARS-CoV-2 strains in paediatric patients. METHODS: In this study, nucleic acid tests (NATs) for SARS-CoV-2 were performed in paediatric outpatients with symptoms of acute respiratory tract infection during 18 Nov-6 Dec, 2022. Half of the outpatients positive for SARS-CoV-2 were randomly selected to screen for other respiratory pathogens, whereas those with low cycle threshold values in SARS-CoV-2 NATs were amplified and sequenced to determine the SARS-CoV-2 variants. Finally, children positive for SARS-CoV-2 with clinical information in detail were enrolled in a follow-up study to identify potential factors significantly associated with long recovery. RESULTS: Among 9625 paediatric outpatients tested for nucleic acid of SARS-CoV-2, 733 (7.62%, 733/9625) were identified as SARS-CoV-2 NAT positive, with only three (0.82%, 3/366) co-infected with other pathogens among 366 randomly selected patients, and 71 (62.83%) determined as Omicron subvariant BF.7 and 42 (37.22%) as BA.5.2 among 113 successfully sequenced. Among the 681 patients with complete clinical information, fever was the most common symptom (96.8%). In a follow-up study of 592 patients, 46.96% became asymptomatic on the third day and 65.71% on the fifth day. Only 1.7% of infected children experienced febrile seizures. Combined with abnormal C-reactive protein, a higher percentage of antibiotics administration was observed. More co-living members and longer duration of first symptoms served as independent risk factors for long-term recovery, especially in children vaccinated for SARS-CoV-2. CONCLUSIONS: BF.7 and BA.5.2 were the dominate Omicron subvariants and caused milder infections during the SARS-CoV-2 outbreak in Beijing. The number of co-living members and duration of first symptoms were independent risk factors for long-term recovery.


Assuntos
COVID-19 , Ácidos Nucleicos , Humanos , Criança , Pequim/epidemiologia , Seguimentos , SARS-CoV-2/genética , COVID-19/epidemiologia
7.
Analyst ; 148(17): 4037-4043, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37522239

RESUMO

As a prognostic biomarker for breast cancer, human epidermal growth factor receptor 2 (HER-2) is of crucial diagnostic value. Here, a label-free electrochemical aptasensor was established for the ultrasensitive detection of HER-2 using a modified electrode of Bi-Sb alloy materials (Bi-Sb AMs). The performance of the aptasensor was enhanced greatly due to the introduction of Bi-Sb alloy materials (Bi-Sb AMs) with high conductivity. Furthermore, by integrating the aptasensor with the Sensit Smart U-disk electrochemical analyzer, the point-of-care testing (POCT) for HER-2 was realized. Under the optimal experimental parameters, the POCT analyzer showed a wide linear response from 0.01 pg mL-1 to 100 ng mL-1, with a low detection limit (LOD) of 5.96 fg mL-1 for the detection of HER-2. The presented POCT analyzer exhibited good specificity, stability, and reproducibility. Benefiting from the simple operation and rapid testing, the developed analyzer will have potential application in the prognostic diagnosis and treatment of breast cancer.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Humanos , Técnicas Eletroquímicas , Ligas , Reprodutibilidade dos Testes , Limite de Detecção , Ouro
8.
Arch Virol ; 168(10): 257, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37755543

RESUMO

Our previous surveillance revealed that t203-like G9 (tentatively designated subtype G9-VI) rotaviruses re-emerged in 2010 in Beijing and rapidly prevailed over the G9-III subtype (the most common G9 subtype globally) and previously predominant G genotypes over the following two years. G9-VI belongs to the VP7 evolutionary lineage VI, which includes unusual and sporadic human rotaviruses from China (t203) and Japan. To obtain insight into the epidemiology, evolution, and transmission advantages of G9-VI rotavirus, we performed follow-up surveillance (2014-2017) and whole-genome analysis of 12 representative G9 strains. The results showed that the G9 genotype was predominant (77.4%), with a marked increase in prevalence (previously 43.5%). Within the G9 genotype, subtype G9-VI accounted for the majority (98.3%) of cases. The most prevalent P-genotype was P[8] (93.7%), within which subtype P[8]b was rare (0.7%). Phylogenetically, the G9-VI subtype strains in this study clustered closely with contemporary emerging human rotaviruses from many other countries in VP7 lineage VI, indicating that this subtype is capable of spreading globally. These currently emerging G9-VI rotaviruses formed a distinct monophyletic subcluster when compared to early G9-VI rotaviruses. Furthermore, four specific amino acid substitutions and synonymous codon substitutions were observed in the VP7 genes between the current G9-VI and globally common G9-III rotaviruses. The remaining nine genes of all of the analyzed representative G9 strains, whether G9-VI or G9-III, combined with the P[8]a, P[8]b, or P[6] genotype and exhibited the same Wa-like backbone constellation.

9.
Mikrochim Acta ; 191(1): 21, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-38091113

RESUMO

This study aimed to develop a quenching-type electrochemiluminescence (ECL) immunosensor for human epidermal growth factor receptor (Her-2) detection. Firstly, Pd/NiFeOx nanoflowers decorated by in situ formation of gold nanoparticles (Au NPs) and 2D Ti3C2 MXene nanosheets were synthesized (AuPd/NiFeOx/Ti3C2) as carriers to load luminol and primary antibodies. Impressively, AuPd/NiFeOx/Ti3C2 with excellent peroxidase-like activity could accelerate the decomposition of the coreactant H2O2 generating more reactive oxygen species (ROSs) under the working potential from 0 to 0.8 V, resulting in highly efficient ECL emission at 435-nm wavelengths. The introduction of tungsten-based polyoxometalate nanoclusters (W-POM NCs) which exhibit remarkable ROSs-scavenging activity as secondary antibody labels could improve the sensitivity of immunosensors. The ZnO nanoflowers were employed to encapsulate minute-sized W-POM NCs, and polydopamine was self-polymerized on the surface of Zn(W-POM)O to anchor secondary antibodies. The mechanism of the quenching strategy was explored and it was found that W-POM NCs could consume ROSs by the redox reaction of W5+ resulting in W6+. The proposed ECL immunosensor displayed a wide linear response range of 0.1 pg·mL-1 to 50 ng·mL-1, and a low detection limit of 0.036 pg mL-1 (S/N = 3). The recoveries ranged from 93.9 to 99.4%, and the relative standard deviation (RSD) was lower than 10%. This finding is promising for the design of detecting new protein biomarkers.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Humanos , Luminol , Espécies Reativas de Oxigênio , Técnicas Biossensoriais/métodos , Tungstênio , Ouro , Peróxido de Hidrogênio , Medições Luminescentes/métodos , Imunoensaio
10.
J Environ Manage ; 335: 117456, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36822044

RESUMO

To enhance the nitrogen removal capacity, scrap iron filings and Si-Al porous clay mineral material (PCMW) was used to improve a subsurface wastewater infiltration system (SWIS). The results showed TN and NH4+-N removal efficiencies of improved SWIS were 20.72% and 5.49% higher than those of the control SWIS, respectively. Based on the response of the removal performance, microbial community and function analysis of 16s rRNA amplicon sequencing results, the amending soil matrix substantially enriched the nitrogen removal bacteria (Rhizobiales_Incertae_Sedis and Gemmatimonadaceae), and significantly improved the activities of key enzymes (Hao, NasAB, NarGHI, NirK, NorBC, NirA and NirBD), particularly at co-occurrence zone of nitrification and denitrification (70-130 cm depth). The amending soil matrix not only extended the growth space of microbes, but also provided additional electrons and carbon sources for denitrifying bacteria by regulating the structure and function of the microbial community. In addition, amending soil matrix could enhance phosphate metabolism genes and phosphate solubilizing microbes in the denitrification zone by increasing the phosphorus source, thus strengthening nitrogen metabolism. Nitrospiraceae, Rhizobiales_Incertae_Sedis and Gemmatimonadaceae related to nitrogen removal and Bacillaceae with phosphate-solubilizing ability could be used as microbial indicators of nitrogen removal in SWISs. The reciprocal action of environmental on microbial characteristics exhibited microbial functional were related to DO, Fe2+, TOC, TP, TN, NH4+-N and NO3--N. Those could be used as physicochemical and biological indicators for application and monitoring of SWIS. In conclusion, this study provided a low-cost and efficient enhancement approach for the application of SWIS in decentralized domestic sewage treatment, and furnished theoretical support for subsequent applications.


Assuntos
Desnitrificação , Águas Residuárias , Fósforo , Nitrogênio/química , RNA Ribossômico 16S , Nitrificação , Bactérias/metabolismo , Fosfatos , Solo , Reatores Biológicos , Esgotos , Eliminação de Resíduos Líquidos
11.
Anal Chem ; 94(37): 12845-12851, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36067524

RESUMO

Ratiometric electrochemiluminescence (ECL) sensors can efficiently remove environmental interference to attain precise detection. Nonetheless, two eligible luminophores or coreactants were usually needed, increasing the complexity and restricting their practical application. In this study, a single luminophore of luminol with a single coreactant of H2O2 was employed to construct a dual-potential ratiometric ECL sensor for the detection of carcinoembryonic antigen (CEA). The produced palladium nanoclusters (Pd NCs) employing a DNA duplex as a template could not only stimulate luminol to produce cathodic ECL (Icathodic) but also quench its anodic ECL (Ianodic). During the detection process, CEA could damage the double-stranded structure and reduce the Pd NCs' amount, triggering a significant decrease in the ratio of Icathodic to Ianodic (Icathodic/Ianodic) and thereby achieving sensitive CEA's detection. Furthermore, the Icathodic/Ianodic was independent of the H2O2 concentration, which avoided a prejudicial effect from H2O2 decomposition and considerably enhanced the detection's reliability. The developed ratiometric ECL sensor demonstrated a sensitive detection toward CEA with a wide linear range from 100 ag/mL to 10 ng/mL and a detection limit of 87.1 ag/mL (S/N = 3). In conclusion, this study offers a new idea for constructing ratiometric ECL sensors based on a single luminophore and technical support for cancer's early diagnosis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Antígeno Carcinoembrionário , DNA/química , Técnicas Eletroquímicas , Peróxido de Hidrogênio , Limite de Detecção , Medições Luminescentes , Luminol/química , Nanopartículas Metálicas/química , Paládio/química , Reprodutibilidade dos Testes
12.
Ecotoxicol Environ Saf ; 243: 114017, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36027715

RESUMO

Urea, nickel (Ni) and dissolved organic matter (DOM) from land varied with different sources have a great impact on the offshore ecosystem. The heterogeneity of Ni bioavailability and toxicity of Prorocentrum donghaiense influenced by DOM fractions incubated in urea was investigated in this study. On the occasion, chlorophyll (Chl a) concentration, growth rate, and photosynthesis parameters were monitored to track changes occurring in the test organism. Chl a concentration and photosynthesis parameters in the treatment of hydrophilic DOM (HPI) with Ni-free was significantly higher than that in the control treatment, and similar data were shown in the treatment of hydrophobic DOM(HPO)with the low Ni environment (0.17µmol L-1). However, the opposite phenomena were observed in the treatments of HPO with the higher Ni environment (over 170µmol L-1). Moreover, the EC50 of Ni for P.donghaiense incubated in HPO was relatively lower than that in HPI and control treatment, which implied that HPO elevated the toxicity of Ni. Therefore, the varied DOM compositions because of different origins, as a chelating agent and potential nutrient source in coastal waters, shows the significantly different bioavailability and toxicity of Ni with the increasing inputs of urea, which in turn influences the dynamics of phytoplankton.


Assuntos
Dinoflagellida , Níquel , Disponibilidade Biológica , Matéria Orgânica Dissolvida , Ecossistema , Níquel/toxicidade , Ureia
13.
J Psychosoc Oncol ; 40(4): 506-518, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34392806

RESUMO

Purpose:Negative emotions can adversely affect the treatment and recovery of breast cancer patients. Post-traumatic stress caused by cancer can increase the negative emotions of patients. This study assessed the relationship between post-traumatic stress and emotional regulation strategies, and the role of emotional regulation in the relationship between post-traumatic stress and negative emotions in breast cancer patients.Design:Cross-sectional questionnaire with sample of 214 Chinese women with breast cancerMethods:Participants completed the Impact of Event Scale-Revised, Hospital Anxiety and Depression Scale, and Emotion Regulation Questionnaire. Correlation and mediation analyses were conducted to assess associations among the scores of these scales.Findings:Patients with low post-traumatic stress chose cognitive reappraisal strategies, while those with high post-traumatic stress chose expressive suppression strategies. Cognitive reappraisal had a significant negative predictive effect on negative emotions, while expressive suppression had a significant positive predictive effect on patient's negative emotions.Conclusions:Cognitive reappraisal may reduce the impact of post-traumatic stress on negative emotions experienced by breast cancer patients. Implications for psychosocial providers or policy: Psychosocial workers in China should conduct cognitive reappraisal training for breast cancer patients with high negative emotions and severe post-traumatic stress. For Chinese breast cancer patients living in other regions, the local oncology social workers should take into account their cultural background and lack of expression, and encourage them to choose cognitive reappraisal strategies.


Assuntos
Neoplasias da Mama , Regulação Emocional , Transtornos de Estresse Pós-Traumáticos , Neoplasias da Mama/psicologia , Neoplasias da Mama/terapia , Cognição , Estudos Transversais , Emoções/fisiologia , Feminino , Humanos
14.
Analyst ; 146(11): 3679-3685, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33955434

RESUMO

In the electrochemiluminescence (ECL) field, most reported luminophores were focused on high-triggering potential and short wavelength, which was adverse for the ECL theory study and application at low potentials. Perylene diimide derivatives could emit near-infrared (NIR) ECL at low-triggering potential; however, they are always highly aggregated into a microrod structure and stacked together, which largely limited their application in biological fields such as bio-sensing and bio-imaging. To overcome these obstacles, we designed a novel perylene diimide molecule, namely N,N'-dicaproate sodium-3,4,9,10-perylenedicarboximide (PDI-COONa). This molecule self-assembled into a two-dimensional network nanostructure, which largely decreased the aggregation degree of PDI molecules and provided solid bases for designing lowly-aggregated PDI molecules. Also, the formed nanoluminophore produced strong emission at -0.26 V with an NIR wavelength 700 nm, which should be due to the excited J-type PDI-COO- dimers. Moreover, this network nanoluminophore well-dispersed on graphene oxide (GO) as an ECL nanomaterial to label secondary antibodies and fabricate a sandwiched immunosensor for alpha-fetoprotein (AFP) detection between 0 and -0.6 V. This immunosensor showed a wider linear response for AFP ranging from 0.1 fg mL-1 to 1 µg mL-1 with a low detection limit 0.0353 fg mL-1 compared with other immunosensors based on PDI microrod-modified GO ECL materials. The fabricated immunosensor also showed good feasibility in human serum samples.


Assuntos
Técnicas Biossensoriais , Perileno , Técnicas Eletroquímicas , Humanos , Imunoensaio , Limite de Detecção , Medições Luminescentes
15.
Analyst ; 146(8): 2705-2711, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33751013

RESUMO

A novel ratiometric electrochemical biosensing strategy based on T7 exonuclease (T7 Exo)-assisted homogenous target recycling coupling hairpin assembly triggered dual-signal output was proposed for the accurate and sensitive detection of microRNA-141 (miRNA-141). Concretely, in the presence of target miRNA, abundant signal transduction probes were released via the T7 Exo-assisted homogenous target recycling amplification, which could be captured by the specially designed ferrocene-labeled hairpin probe (Fc-H1) on -electrode interface and triggered the nonenzymatic catalytic hairpin assembly (Fc-H1 + MB-H2) to realize the cascade signal amplification and dual-signal output. Through such a conformational change process, the electrochemical signal of Fc (IFc) and MB (IMB) is proportionally and substantially decreased and increased. Therefore, the signal ratio of IMB/IFc can be employed to accurately reflect the true level of original miRNA. Benefiting from the efficient integration of the T7 Exo-assisted target recycle, nonenzymatic hairpin assembly and dual-signal output mode, the proposed sensor could realize the amplified detection of miRNA-141 effectively with a wide detection range from 1 fM to 100 pM, and a detection limit of 200 aM. Furthermore, it exhibits outstanding sequence specificity to discriminate mismatched RNA, acceptable reproducibility and feasibility for real sample. This strategy effectively integrated the advantages of multiple amplification and ratiometric output modes, which could provide an accurate and efficient method in biosensing and clinical diagnosis.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Técnicas Eletroquímicas , Exodesoxirribonucleases , Limite de Detecção , MicroRNAs/genética , Reprodutibilidade dos Testes
16.
BMC Infect Dis ; 21(1): 722, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34332544

RESUMO

BACKGROUND: The aim of the present study was to develop a clinical scoring system for the diagnosis of hand-foot-mouth disease (HFMD) with improved accuracy. METHODS: A retrospective analysis was performed on standardized patient history and clinical examination data obtained from 1435 pediatric patients under the age of three years who presented with acute rash illness and underwent enterovirus nucleic acid detection. Patients were then divided into the HFMD (1094 patients) group or non-HFMD (341 patients) group based on a positive or a negative result from the assay, respectively. We then divided the data into a training set (1004 cases, 70%) and a test set (431 cases, 30%) using a random number method. Multivariate logistic regression was performed on 15 clinical variables (e.g. age, exposure history, number of rash spots in a single body region) to identify variables highly predictive of a positive diagnosis in the training set. Using the variables with high impact on the diagnostic accuracy, we generated a scoring system for predicting HFMD and subsequently evaluated this system in the test set by receiver operating characteristic curve (ROC curve). RESULTS: Using the logistic model, we identified seven clinical variables (age, exposure history, and rash density at specific regions of the body) to be included into the scoring system. The final scores ranged from - 5 to 24 (higher scores positively predicted HFMD diagnosis). Through our training set, a cutoff score of 7 resulted in a sensitivity of 0.76 and specificity of 0.68. The area under the receiver operating characteristic curve (AUC) was 0.804 (95% confidence interval [CI]: 0.773-0.835) (P < 0.001). Using the test set, we obtained an AUC of 0.76 (95% CI: 0.710-0.810) with a sensitivity of 0.76 and a specificity of 0.62. These results from the test set were consistent with those from the training set. CONCLUSIONS: This study establishes an objective scoring system for the diagnosis of typical and atypical HFMD using measures accessible through routine clinical encounters. Due to the accuracy and sensitivity achieved by this scoring system, it can be employed as a rapid, low-cost method for establishing diagnoses in children with acute rash illness.


Assuntos
Infecções por Enterovirus , Enterovirus , Doença de Mão, Pé e Boca , Criança , Pré-Escolar , Doença de Mão, Pé e Boca/diagnóstico , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Lactente , Curva ROC , Estudos Retrospectivos
17.
Mikrochim Acta ; 189(1): 17, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873664

RESUMO

As well known, the electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)32+) heavily relies on highly positive or negative triggered voltage, prejudicing the detection toward the bio-molecules. In this work, Ru(bpy)32+ could generate enhanced and stable ECL at a low potential of 0.05 V (vs. Ag/AgCl) on graphene-PtPd hybrid, attributing to its excellent electrocatalysis from the synergistic effect between Pt and Pd. The obtained low-potential-driven ECL could be quenched by MoS2 nanoflowers. Based on the quenching effect, a sandwich "signal-off" ECL immunosensor was fabricated to sensitively detect carcinoembryonic antigen (CEA). A linear calibration curve from 1 fg mL-1 to 1 ng mL-1 was obtained along with a low detection limit of 0.54 fg mL-1 (S/N = 3) under optimal conditions. The sensor showed satisfactory specificity, stability, and reproducibility and was successfully applied to determine CEA in actual samples. The recoveries ranged from 98.80 to 100.23%, and the relative standard deviation (RSD) was lower than 5%. Above all, this work explored new materials in low-potential-driven ECL system and provided a reliable sensing strategy for clinical applications.


Assuntos
Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Substâncias Luminescentes/química , Nanocompostos/química , Compostos Organometálicos/química , Anticorpos Imobilizados/imunologia , Antígeno Carcinoembrionário/imunologia , Dissulfetos/química , Grafite/química , Humanos , Limite de Detecção , Molibdênio/química , Paládio/química , Platina/química , Reprodutibilidade dos Testes
18.
Analyst ; 145(10): 3605-3611, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32266898

RESUMO

A sensitive and enzyme-free electrochemical aptasensor was constructed for the sensing of 8-hydroxy-2'-deoxyguanosine (8-OH-dG). In the process of constructing the aptasensor, triple signal amplification strategies were introduced to enhance the sensitivity. First, every aptamer/pDNA complex immobilized on magnetic beads could release three kinds of pDNAs when 8-OH-dG was introduced, which caused three-fold magnification of the target. Second, the released three kinds of pDNAs initiated catalyzed hairpin assembly between two hairpin DNAs (HP1 and HP2) on a gold electrode. Meanwhile, the three kinds of pDNAs were released again by a strand displacement reaction to obtain the next catalyzed hairpin assembly. Third, the emerging toehold of HP2 further induced a hybridization chain reaction (HCR) between two hairpin DNAs (HP3 and HP4), forming a long double-stranded DNA concatemer on the surface of the electrode. Finally, [Ru(NH3)6]3+, an electroactive cation, was adsorbed onto the long dsDNA concatemer by electrostatic interactions and consequently, an electrochemical signal was generated. Under this triple signal amplification, a low detection limit down to 24.34 fM has been obtained for 8-OH-dG determination, which is superior to those of most previously reported methods.


Assuntos
8-Hidroxi-2'-Desoxiguanosina/análise , Biocatálise , Técnicas Biossensoriais/métodos , DNA/química , DNA/genética , Sequências Repetidas Invertidas , 8-Hidroxi-2'-Desoxiguanosina/química , 8-Hidroxi-2'-Desoxiguanosina/urina , Aptâmeros de Nucleotídeos/metabolismo , Eletroquímica , Humanos , Hibridização de Ácido Nucleico
19.
Molecules ; 24(4)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781358

RESUMO

The aim of this study was to evaluate the antioxidant activities of extracts from olive leaves (EOL). The main contents of EOL were determined by colorimetric methods. The antioxidant activities were assessed by measuring the scavenging free radicals in vitro. To investigate the antioxidant activity in vivo, we detected the survival of Caenorhabditis elegans, under thermal stress. Subsequently the reactive oxygen species (ROS) level, activities of antioxidant enzymes, the expression of HSP-16.2 and the translocation of daf-16 were measured. The results showed that, polyphenols was the main component. EOL could well scavenge DPPH and superoxide anion radicals in vitro. Compared to the control group, the survival rate of C. elegans treated with EOL was extended by 10.43%, under heat stress. The ROS level was reduced, while the expression of hsp-16.2 was increased to protect the organism against the increasing ROS. The level of malondialdehyde (MDA) also decreased sharply. The activities of inner antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) were potentiated, which might have had a correlation with the DAF-16 transcription factor that was induced-turned into the nuclear. Therefore, EOL showed a strong antioxidant ability in vitro and in vivo. Hence, it could be a potential candidate when it came to medicinal and edible plants.


Assuntos
Antioxidantes/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Olea/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Animais , Antioxidantes/isolamento & purificação , Metanol , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Polifenóis/isolamento & purificação , Espécies Reativas de Oxigênio
20.
BMC Infect Dis ; 16(1): 508, 2016 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-27663354

RESUMO

BACKGROUND: Diarrhea caused by viruses is a global problem among young children. We investigated two of the most important agents, rotavirus and adenovirus, to provide epidemiological evidence for a better understanding of their role among children with acute diarrhea. METHODS: A total of 3147 hospitalized children were enrolled in the study during 2010 ~ 2014. Antigen testing for rotavirus and DNA testing for adenovirus were performed on stool specimens collected from participants. RESULTS: There were 1985 cases of community-acquired diarrhea (CAD) and 1162 cases of hospital-acquired diarrhea (HAD). A total of 692 cases (22.0 %) were positive for rotavirus. Rotavirus was detected in more children with HAD than in those with CAD (24.6 %; 286/1162 vs. 20.5 %; 406/1985). A total of 324 cases (10.3 %) were adenovirus positive. There was a significant difference between the CAD group and HAD group (9.5 %; 188/1985 vs. 11.7 %; 136/1162: χ 2 = 3.957, p = 0.047). Co-infection was found in only 35 children (1.11 %), and the co-infection rate was similar between the CAD and HAD groups (χ 2 = 1.174, p = 0.279). There was no association between sex and the detection rate of these viruses. The positive rate was significantly different for rotavirus among CAD cases (χ 2 = 27.979, p < 0.001) and for adenovirus (χ 2 = 34.362, p < 0.001) in the five age groups. Compared with the other four age groups (15.8-19.8 %), the prevalence of rotaviruses was highest among children aged 12-24 months (28.6 %). Adenovirus was detected in 3.6 % of neonates compared with 5.8 % of infants from 1 to 6 months old; this increased to 12.0-13.8 % in children over 6 months of age. In HAD cases, age differences were not found for rotavirus and adenovirus. Seasonal variation of rotavirus was observed, with peaks in November and December and with through in July and August; however, no clear seasonal pattern was found for adenovirus. CONCLUSION: Detection rates for rotavirus and adenovirus were significantly higher in children with HAD than those with CAD, but co-infection was very low. A high prevalence of rotavirus was identified in neonates with diarrhea. Vaccination for rotavirus gastroenteritis should be considered in neonates.

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