Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 78
Filtrar
1.
Anal Chem ; 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39134457

RESUMO

Circulating tumor DNA (ctDNA) is a critical biomarker for early tumor detection. However, accurately quantifying low-abundance ctDNA in human serum remains a significant challenge. To address this challenge, we introduce a bimodal biosensor tailored for detecting the epidermal growth factor receptor (EGFR) mutation L858R in specific nonsmall cell lung cancer (NSCLC) patients. This biosensor utilizes dual CRISPR-Cas12a systems to quantify the target via fluorescence and electrochemical signals. In our system, the EGFR L858R exhibits resistance to digestion by the restriction enzyme MscI, which activates the first CRISPR-Cas12a protein and inhibits the binding of magnetic beads with fluorescein (FAM)-labeled hybridization chain reaction (HCR) products, thereby reducing the fluorescence signal. This activation also inhibits the cleavage activity of the second CRISPR-Cas12a protein, allowing the electrode to sustain a higher electrochemical signal from nanomaterials. The wild-type EGFR (wt EGFR) produces the opposite effect. Consequently, the concentration of EGFR L858R can be accurately quantified and verified using both fluorescence and electrochemical signals. The biosensor offers a dynamic detection ranging from 10 fM to 1 µM, with a detection limit of 372 aM. It demonstrates excellent specificity, reproducibility, stability, and recovery rates. Moreover, the sensor's enhanced analytical sensitivity highlights its critical role in biosensing applications and early disease diagnosis.

2.
Anal Biochem ; 692: 115571, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38796119

RESUMO

Markers of myocardial injury, such as myoglobin (Mb), are substances swiftly released into the peripheral bloodstream upon myocardial cell injury or altered cardiac activity. During the onset of acute myocardial infarction, patients experience a significant surge in serum Mb levels. Given this, precise detection of Mb is essential, necessitating the development of innovative assays to optimize detection capabilities. This study introduces the synthesis of a three-dimensional hierarchical nanocomposite, Cubic-ZIF67@Au-rGOF-NH2, utilizing aminated reduced graphene oxide and zeolite imidazolium ester framework-67 (ZIF67) as foundational structures. Notably, this novel material, applied in a label-free electrochemical immunosensor, presents a groundbreaking approach for detecting myocardial injury markers. Experimental outcomes revealed ZIF67 and AuNPs exhibit enhanced affinity and growth on the 3D-rGOF-NH2 matrix, thus amplifying electrical conductivity while preserving the inherent electrochemical attributes of ZIF67. As a result, the Cubic-ZIF67@Au-rGOF-NH2 label-free electrochemical immunosensor exhibited a broad detection range and high sensitivity for Mb. The derived standard curve was ΔIp = 16.67552lgC+275.245 (R = 0.993) with a detection threshold of 3.47 fg/ml. Moreover, recoveries of standards spiked into samples ranged between 96.3% and 108.7%. Importantly, the devised immunosensor retained notable selectivity against non-target proteins, proving its potential clinical utility based on exemplary sample analysis performance.


Assuntos
Técnicas Eletroquímicas , Ouro , Grafite , Estruturas Metalorgânicas , Mioglobina , Mioglobina/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Estruturas Metalorgânicas/química , Ouro/química , Humanos , Técnicas Biossensoriais/métodos , Nanocompostos/química , Zeolitas/química , Imidazóis/química , Limite de Detecção , Nanopartículas Metálicas/química
3.
Anal Biochem ; 676: 115233, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37433362

RESUMO

Exosomes derived from lung cancer typically contain the genetic information of the donor cells. Therefore, exosomes contribute to early diagnosis, treatment effectiveness evaluation, and prognosis assessment of cancer. Based on the biotin-streptavidin system and MXenes nanomaterial, a dual-effect amplification method had been developed to construct an ultrasensitive colorimetric aptasensor for detecting exosomes. MXenes can enhance the loading of aptamer and biotin as the high specific surface area. Biotin-streptavidin system can increase the amount of horseradish peroxidase-linked (HRP-linked) streptavidin, considerably boosting the color signal of the aptasensor. The proposed colorimetric aptasensor exhibited excellent sensitivity, with a detection limit of 42 particles µL-1 and a linear range of 102 to 107 particles µL-1. The constructed aptasensor showed satisfactory reproducibility, stability, and selectivity, confirming the promising application of exosomes in clinical cancer detection.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Exossomos , Estreptavidina , Biotina , Reprodutibilidade dos Testes , Técnicas Biossensoriais/métodos , Limite de Detecção
4.
Nutr Metab Cardiovasc Dis ; 33(12): 2464-2470, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37798231

RESUMO

BACKGROUND AND AIMS: Hyperuricemia has become a vital public health problem affecting the health of residents. The visceral fat area (VFA) is closely related to many chronic diseases. However, the association between VFA and hyperuricemia within the Chinese adult population remains nebulous. The aim of the research is to assess the relationship between VFA and serum uric acid levels. METHODS AND RESULTS: From June 2020 to June 2021, a total of 340 Chinese adults (240 in the control group and 100 in the hyperuricemia group) were recruited from the physical examination center of Hongqi Hospital Affiliated to Mudanjiang Medical University. General demographic characteristics were collected by questionnaire. VFA was measured by a body composition analyzer, and serum biochemical indices were detected by clinical laboratory. VFA in the hyperuricemia group was higher than in the control group (P<0.05). Further, VFA demonstrated a positive correlation with serum uric acid level (rs = 0.370, P<0.001). To further explore this relationship, we divided the VFA into quartiles (<P25, P25-P50, P50-P75, ≥P75). Upon comparison with the <P25 group, we found the VFA in the P25-P50, P50-P75, and ≥P75 groups to be associated with a substantially escalated risk of hyperuricemia, even after adjusting for age, gender, body weight, fasting plasma glucose, calcium, alanine transaminase, urea, alkaline phosphatase, and γ-glutamyltransferase. The OR and 95% CI were 2.547 (1.023, 6.341), 3.788 (1.409, 10.187) and 3.723 (1.308, 10.595), respectively (P<0.05). CONCLUSION: VFA has a positive correlation with serum uric acid levels and may serve as a crucial predictive marker for hyperuricemia.


Assuntos
Hiperuricemia , Ácido Úrico , Humanos , Adulto , Estudos Transversais , Gordura Intra-Abdominal , Hiperuricemia/diagnóstico , Hiperuricemia/epidemiologia , População do Leste Asiático
5.
Mikrochim Acta ; 190(4): 147, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36947252

RESUMO

The detection signal of carbohydrate antigen 125 (CA125) can be quantitatively amplified via the dual metal-organic framework (MOF) sandwich strategy. We propose a versatile method for synthesizing uniform MXene and MIL-101(Fe)-NH2 composites that combine the advantages of both materials to build a base layer with superb performance. MXene exhibits excellent electrical conductivity and high surface area. The mesoporous MIL-101(Fe)-NH2 not only increases the loading capacity of the primary antibody but also possesses the catalytic activity of the metal center (Fe). UiO66 loaded with methylene blue (MB) was fabricated as an electrochemical immunosensor signal tag to enable the detection of CA125. The mixture of MXene and MIL-101(Fe)-NH2 prepared as the substrate was fixed by chitosan rich in amino groups. As the signal amplification sector, UiO66@MB enhanced secondary antibody loading capacity and generated a redox signal enabling the detection of antigenic substances. The proposed electrochemical immunosensor demonstrated high sensitivity with a low limit of detection (LOD) of 0.006 U/mL. Therefore, the dual MOF sandwich-based immunosensor provides a novel method for the early diagnosis of CA125.


Assuntos
Biomarcadores Tumorais , Técnicas Biossensoriais , Técnicas Biossensoriais/métodos , Anticorpos Imobilizados , Imunoensaio/métodos , Anticorpos , Antígeno Ca-125 , Azul de Metileno/química
6.
Mikrochim Acta ; 190(9): 366, 2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37615746

RESUMO

The excessive utilization of antibiotics has led to significant water contamination and posed severe threats to human well-being. Consequently, the pressing imperative to identify antibiotics in the environment arises. In this study, we have successfully synthesized a hollow PCN-222 MOF distinguished by its substantial surface area and abundant functional groups, particularly the porphyrin cores. To augment the electrical conductivity of the hollow PCN-222 (HPCN-222), gold (Au) particles were incorporated within the porphyrin core using a fundamental hydrothermal method. This modification facilitated the effective immobilization of aptamer strands through π-π stacking and electrostatic interactions. As a result, the Au@HPCN-222 composite demonstrated exceptional efficacy as a substrate for immobilizing the aptamer (Apt) onto the GCE surface. By employing differential pulse voltammetry (DPV) we successfully achieved the detection of chloramphenicol (CAP) with a remarkably low limit of detection of 0.0138 ng mL-1 and the peak DPV currents at 0.18 V (vs. Ag/AgCl) were used for calibration. Furthermore, this aptasensor exhibited high selectivity and reproducibility.


Assuntos
Cloranfenicol , Porfirinas , Humanos , Reprodutibilidade dos Testes , Antibacterianos , Calibragem , Oligonucleotídeos
7.
Nutr Metab Cardiovasc Dis ; 31(8): 2449-2457, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34154888

RESUMO

BACKGROUND AND AIMS: Hyperuricemia (HUA) were associated with Metabolic syndrome (MetS) and its components. However, the molecular mechanism of uric acid in the development of MetS was not well elucidated. The aim of this study was developing a systemic metabolic profile by using metabolomics approach to explore the molecular mechanism of uric acid in the development of MetS. METHODS AND RESULTS: Anthropometric, clinical biochemical data, and serum samples were collected from patients with MetS, MetS combined with HUA (MetS & HUA) and healthy controls. 1H nuclear magnetic resonance (NMR) spectroscopy was used to detect endogenous small molecule metabolites of serum samples, then multivariate statistical analysis was applied to distinguish samples of different groups. In addition, pathway analysis was performed to contribute to understanding the metabolic change. By serum metabolic profiling, a total of 20 identified metabolites including lipids, amino acids, and organic acids were significantly altered in MetS and MetS & HUA patients. MetS & HUA patients presented a more severe disorder in both identified metabolites and BMI and biochemical indexes. According to pathway analysis, there were 3 and 5 metabolic pathways remarkably perturbed in MetS and MetS & HUA group respectively. CONCLUSION: Taken together, we identified disordered metabolites and related pathways for both MetS and MetS & HUA patients, and found a more severe metabolic disorder in MetS patients who has a higher serum uric acid. Our study provides biochemical insights into the metabolic alteration for the progress of MetS.


Assuntos
Metabolismo Energético , Hiperuricemia/diagnóstico , Síndrome Metabólica/diagnóstico , Metaboloma , Metabolômica , Espectroscopia de Prótons por Ressonância Magnética , Ácido Úrico/sangue , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Progressão da Doença , Humanos , Hiperuricemia/sangue , Masculino , Síndrome Metabólica/sangue , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Índice de Gravidade de Doença
8.
Biotechnol Appl Biochem ; 68(6): 1192-1201, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32970340

RESUMO

In our work, one-step electro-deposition method was adopted to produce polyaniline (PANI) and functional multiwalled carbon nanotubes (f-MWCNTs) films on glass carbon electrodes, and the modified electrodes were applied as an electrochemical sensor for determination of 10-hydroxycamptothecine (10-HCPT). The f-MWCNTs were handled by ultrasound processing in concentrated oxidizing acid solution, which can obtain a wonderful dissolution in water and attach new functional groups, such as -COOH and -OH. Then, aniline monomer could polymerize on the surface easily. The surface characterization was investigated using various techniques including scanning electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, and electro-catalytic properties were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Under optimal conditions, the resulting of PANI/f-MWCNTs sensor showed a wide linear range (3 × 10-9 to 7 × 10-7 mol L-1 ) and a low detection limit (1 × 10-9 mol L-1 ), which is attributing to its large special surface area and good conductivity. Moreover, the modified electrodes are convenient to fabricate, which can be used to detect 10-HCPT in urine samples successfully.


Assuntos
Compostos de Anilina/química , Técnicas Biossensoriais , Camptotecina/análogos & derivados , Técnicas Eletroquímicas , Nanotubos de Carbono/química , Camptotecina/análise , Eletrodos
9.
Biomed Chromatogr ; 35(4): e5032, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33220100

RESUMO

The aim of this study was to evaluate the effects of a natural soda water [Shi Han Quan (SHQ)] on hyperglycemia and plasma metabolic profiling and explore the mechanism using metabolomics techniques. Kun-Ming mice weighing 26 ± 2 g were used for the hyperglycemia animal model with alloxan and divided into control, hyperglycemia (HG), and HG + SHQ soda water (SHQ) groups. The experiment lasted for 30 days. The plasma metabolomic profiling of mice was determined using ultrahigh-pressure liquid chromatography-quadrupole-time of flight-mass spectrometry. After the mice drank SHQ soda water, the levels of insulin and blood glucose were significantly lower in the SHQ group compared with the control group, and the level of insulin sensitivity [insulin sensitivity index (ISI)] was significantly higher in the SHQ group compared with the HG group. The mice in the different groups after SHQ intervention could be separated into distinct clusters, and nine major plasma metabolites with significant differences between groups were found closely associated with blood glucose and ISI. The metabolic pathway analysis of these metabolites involved abnormal fatty acid oxidation and phospholipid, acylcarnitine, and corticoid metabolism. The results suggested the metabolic changes and possible mechanism of SHQ improving the alloxan-induced HG, and the findings provided insights into the prevention and control of HG and diabetes.


Assuntos
Água Carbonatada , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Metaboloma/efeitos dos fármacos , Camundongos Obesos/metabolismo , Animais , Biomarcadores/sangue , Resistência à Insulina , Masculino , Metabolômica , Camundongos , Reprodutibilidade dos Testes
10.
Mikrochim Acta ; 188(6): 213, 2021 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-34052919

RESUMO

A sandwich-format electrochemiluminescence (ECL) immunosensor has been developed for alpha-fetoprotein (AFP) detection based on the use of ordered mesoporous carbon-molybdenum disulfide (OMC-MoS2) as a sensor platform and cuprous oxide @ ordered mesoporous carbon-Ru(bpy)32+ (Cu2O@OMC-Ru) composites as signal tags. OMC alongside MoS2 plays a synergistic role in improving the electrochemical performance of the electrode in the electron transfer process. The uniform cubic-shaped Cu2O@OMC-Ru nanocrystals display excellent luminous efficiency, with a signal amplification strategy of OMC-MoS2 synergistic enhancement and Cu2O@OMC which is capable of immobilizing more Ru(bpy)32+ serving as a tracing tag to label antibodies. A detectable ECL emission at a Cu2O@OMC-Ru nanocrystals modified electrode is initiated at an applied voltage of +1.15 V (scanning range: 0-1.2 V), in the presence of the tripropylamine (TPA) as coreactant. With the increase in AFP concentration, the loading of Cu2O@OMC-Ru at the electrode increases. Afterward, the ECL detection of AFP shows a wide linear range from 0.1 pg/mL to 10 ng/mL with a correlation coefficient of 0.9964 and a detection limit of 0.011 pg/mL (S/N = 3) under the optimal experimental conditions. The recoveries were in the range 91.2-97.1% with RSD varying from 4.8 to 8.5%. Overall, the novel immunosensor has been successfully applied to the analysis of human serum samples, indicating a great potential for application in clinical diagnostics.


Assuntos
Biomarcadores Tumorais/sangue , Imunoensaio/métodos , Nanopartículas Metálicas/química , Nanocompostos/química , alfa-Fetoproteínas/análise , Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/imunologia , Carbono/química , Cobre/química , Dissulfetos/química , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Limite de Detecção , Medições Luminescentes/métodos , Molibdênio/química , Compostos Organometálicos/química , Porosidade , Reprodutibilidade dos Testes , alfa-Fetoproteínas/imunologia
11.
Mikrochim Acta ; 187(5): 264, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32270338

RESUMO

An electrochemical immunoassay for the carcinoembryonic antigen is described. It is based on the use of Au NPs modified zeolitic imidazolate framework (ZIF-8) and ordered mesoporous carbon (OMC). Au NPs@ZIF-8 was synthesized by reduction of chloroauric acid. It serves as immobilization support nanocarrier to increase antibody loading due to its large surface area. OMC was dropped on a glassy carbon electrode to improve electrochemical signals due to enhanced electrical conductivity. Differential pulse voltammetry was carried out to record electrochemical responses (best measured at 0.26 V vs. Ag/AgCl). The immunosensor demonstrated excellent electrochemical performance with a linear determination range of 5 pg mL-1 to 400 ng mL-1 and a determination limit of 1.3 pg mL-1 (S/N = 3). The sensor also exhibited high selectivity, good stability, and acceptable reproducibility. Graphical abstract Scheme 1 Schematic representation of fabrication of the immunosensor for CEA determination.


Assuntos
Carbono/química , Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Anticorpos Imobilizados/imunologia , Antígeno Carcinoembrionário/imunologia , Ouro/química , Humanos , Limite de Detecção , Porosidade , Reprodutibilidade dos Testes
12.
Mikrochim Acta ; 187(9): 500, 2020 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-32803374

RESUMO

A novel "signal-on" electrochemical aptasensor was developed for ultrasensitive and specific detection of BPA, using single-walled carbon nanotubes (SWCNT) as the electro-catalytic probe for further signal amplification. The multi-walled carbon nanotubes (MWCNT), amino-functionalized magnetite, and gold nanoparticles (NH2-Fe3O4/Au NPs) were applied first to modify the glassy carbon electrode (GCE) surface and to form a nanomaterial film with satisfactory conductive properties, stability, and biocompatibility. The BPA aptamer was then loaded onto the sensing platform by hybridization with complementary DNA (CDNA). In the presence of BPA it combines with the aptamer and the BPA-aptamer conjugate was released from the electrode;subsequently the added SWCNT and CDNA assembled quickly. Thus, the dual-amplification of the "signal-on" electrochemical aptasensor takes effect. The [Fe (CN)6]3-/4- redox probe signal (∆I) detected by DPV (differential pulse voltammetry) is proportional to the negative logarithm of BPA concentration between 10-19 M and 10-14 M. The detection limit is 0.08 aM. Importantly, the proposed biosensor represents a successful application for determination of BPA in human serum and lake water. Schematic representation of SWCNT-amplified "signal-on" electrochemical aptasensor for the detection of trace level of bisphenol A in human serum and lake water.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos Benzidrílicos/sangue , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono/química , Fenóis/sangue , Sequência de Bases , Técnicas Biossensoriais/instrumentação , DNA/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Óxido Ferroso-Férrico/química , Ouro/química , Humanos , Ácidos Nucleicos Imobilizados/química , Lagos/análise , Limite de Detecção , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes
13.
J Clin Lab Anal ; 32(3)2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28940690

RESUMO

BACKGROUND: Cellular and brain metabolism of dopamine can be correlated with a number of neurodegenerative disorders, our study was to explore a simple and efficient method to detect dopamine in real samples. METHODS: A new quantum dots (CdTe QDs) could be prepared using the hydrothermal method, the electrochemical biosensor was established by dropping CdTe QDs on the surface of glassy carbon electrode (GCE). RESULTS: The CdTe QDs/GCE exhibited the excellent electrochemical catalytic activity toward dopamine (DA) with good stability and high sensitivity in presence of interfering substances. The detection limit of DA was calculated by differential pulse voltammetry (DPV) as low as 0.3 µmol L-1 with a linear dynamic range of 1 µmol L-1 to 400 µmol L-1 . CONCLUSION: In this paper, the proposed electrochemical biosensor could be effectively used for the direct and rapid detection of DA in human serum and urine samples.


Assuntos
Compostos de Cádmio/química , Dopamina/sangue , Dopamina/urina , Técnicas Eletroquímicas/métodos , Pontos Quânticos/química , Telúrio/química , Carbono/química , Eletrodos , Vidro/química , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
14.
Anal Biochem ; 519: 92-99, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-27919603

RESUMO

The assembly of quantum dots (QDs) in a simply method opens up opportunities to obtain access to the full potential of assembled QDs by virtue of the collective properties of the ensembles. In this study, quantum dots CdTe and graphene (Gr) nanocomposite was constructed for the simultaneous determination of uric acid (UA) and dopamine (DA). The CdTe QDs-Gr nanocomposite was prepared by ultrasonication and was characterized with microscopic techniques. The nanocomposite modified electrode was characterized by cyclicvoltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Due to the synergistic effects between CdTe QDs and Gr, the fabricated electrode exhibited excellent electrochemical catalytic activities, good biological compatibility and high sensitivity toward the oxidation of UA and DA. Under optimum conditions, in the co-existence system the linear calibration plots for UA and DA were obtained over the range of 3-600 µM and 1-500 µM with detection limits of 1.0 µM and 0.33 µM. The fabricated biosensor also exhibits the excellent repeatability, reproducibility, storage stability along with acceptable selectivity.


Assuntos
Técnicas Biossensoriais/métodos , Compostos de Cádmio/química , Dopamina/urina , Grafite/química , Nanocompostos/química , Pontos Quânticos , Telúrio/química , Ácido Úrico/urina , Espectroscopia Dielétrica , Eletrodos , Humanos , Limite de Detecção , Oxirredução , Reprodutibilidade dos Testes
15.
Biomed Chromatogr ; 31(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28214354

RESUMO

Primary angle-closure glaucoma (PACG) is a severe chronic neurodegenerative disease in Asia. Identification of important metabolites associated with PACG is crucial for early intervention and advancing knowledge of the disease mechanism. We applied gas chromatography-mass spectrometry (GC-MS) for targeted metabolomic analysis on serum samples from 38 newly diagnosed PACG patients and 48 controls. Palmitoleic acid (PA), linoleic acid (LA), γ-linolenic acid (GLA) and arachidonic acid (ARA) were identified as important metabolites associated with PACG. PA and GLA were significantly elevated (p < 0.05), while LA and ARA showed a significantly decreased trend (p < 0.05) in PACG group compared with the control group. Also, significant negative correlations were observed between LA and ARA levels and intraocular pressure of the left eye (rs = -0.750, p < 0.001; rs = -0.729, p < 0.001) and the right eye (rs = -0.786, p < 0.001; rs = -0.764, p < 0.001). Serum GLA level was positively correlated with intraocular pressure of the left eye (rs = 0.233, p = 0.031) and the right eye (rs = 0.226, p = 0.036). Our findings revealed a significant difference of the serum free fatty acid metabolic profiles between PACG patients and control subjects. Furthermore, PA, LA, ARA and GLA appear to have clinical applications for the screening of PACG.


Assuntos
Ácidos Graxos Insaturados/sangue , Ácidos Graxos Insaturados/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Glaucoma de Ângulo Fechado/metabolismo , Metabolômica/métodos , Idoso , Biomarcadores/sangue , Análise Discriminante , Feminino , Humanos , Masculino , Metaboloma , Pessoa de Meia-Idade , Análise de Componente Principal , Curva ROC , Reprodutibilidade dos Testes
16.
J AOAC Int ; 98(5): 1260-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26525244

RESUMO

Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of uric acid (UA) at a CdTe quantum dot (QD) modified the glassy carbon electrode (GCE). CdTe QDs, as new semiconductor nanocrystals, can greatly improve the peak current of UA. The anodic peak current of UA was linear with its concentration between 1.0×10(-6) and 4.0×10(-4) M in 0.1 M pH 5.0 phosphate buffer solution. The LOD for UA at the CdTe electrode (1.0×10(-7) M) was superior to that of the GCE. In addition, we also determined the effects of scan rate, pH, and interferences of UA for the voltammetric behavior and detection. The results indicated that modified electrode possessed excellent reproducibility and stability. Finally, a new and efficient electrochemical sensor for detecting UA was developed.


Assuntos
Compostos de Cádmio/química , Técnicas Eletroquímicas/instrumentação , Pontos Quânticos/química , Telúrio/química , Ácido Úrico/sangue , Soluções Tampão , Carbono/química , Eletrodos , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Reprodutibilidade dos Testes
17.
J AOAC Int ; 98(6): 1728-32, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26651586

RESUMO

To develop a new electrochemical DNA biosensor for determination of Klebsiella pneumoniae carbapenemase, a highly sensitive and selective electrochemical biosensor for DNA detection was constructed based on a glassy carbon electrode (GCE) modified with gold nanoparticles (Au-nano). The Au-nano/GCE was characterized by scanning electromicroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The hybridization detection was measured by differential pulse voltammetry using methylene blue as the hybridization indicator. The dynamic range of detection of the sensor for the target DNA sequences was from 1 × 10(-11) to 1 × 10(-8) M, with an LOD of 1 × 10(-12) M. The DNA biosensor had excellent specificity for distinguishing complementary DNA sequence in the presence of non-complementary and mismatched DNA sequence. The Au-nano/GCE showed significant improvement in electrochemical characteristics, and this biosensor was successfully applied for determination of K. pneumoniae.


Assuntos
Proteínas de Bactérias/análise , Técnicas Biossensoriais/métodos , Klebsiella pneumoniae/enzimologia , Nanopartículas Metálicas/química , Oligonucleotídeos/genética , beta-Lactamases/análise , Carbono , Eletroquímica , Eletrodos , Ouro , Hibridização de Ácido Nucleico
18.
J Am Coll Nutr ; 33(5): 406-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25079310

RESUMO

PURPOSE: To evaluate and compare the levels of free fatty acids between senile cataract patients and normal controls. METHODS: Fifty consecutive patients with newly diagnosed senile cataract and 50 age- and gender-matched controls were evaluated. Subjects/patients were randomized according to selection criteria. The levels of free fatty acids (FFAs) in serum were measured by gas chromatography-mass spectrometry (GC-MS). Sixteen fatty acids from 14:0 to 24:1 were identified. The values were compared between cataract and control groups by parametric independent sample test and Mann-Whitney U tests. RESULTS: A significant decrease was observed in arachidonic acid (C20:4n-6, ARA), cis-4,7,10,13,16,19-docosahexaenoic acid (C22:6n-3, DHA), tetracosanoic acid (C24: 0), cis-7,10,13,16,19-docosapentaenoic acid (C22:5n-6, DPA), total n-3 long-chain polyunsaturated fatty acids (LC-PUFAs), total n-6 LC-PUFAs, total fatty acids, unsaturated fatty acids (USFAs), polyunsaturated fatty acids (PUFAs), and nonessential fatty acid levels in patients with senile cataract in comparison with healthy persons (p < 0.05). CONCLUSIONS: The levels of FFA including DPA, tetracosanoic acid, ARA, and DHA were significantly lower in the senile cataract group compared to that in the normal controls. FFA may be helpful in preventing senile cataract.


Assuntos
Catarata/sangue , Ácidos Graxos não Esterificados/sangue , Ácidos Graxos Insaturados/sangue , Ácidos Graxos/sangue , Idoso , Ácido Araquidônico/sangue , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Graxos Ômega-3/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Talanta ; 269: 125412, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37984234

RESUMO

A "signal-on" electrochemiluminescence (ECL) immunosensor has been proposed for detecting carbohydrate antigen 153 (CA153) based on the dual MOFs sandwich strategy. The conductive and porous substrate consisting of 1T-MoS2 and two-dimensional conductive metal-organic framework (MOF, Ni-HAB) was anchored onto the glassy carbon electrode (GCE) to label the capture antibody (Ab1), and the luminescence-functionalized MOF (Ru(bpy)32+@UiO-66-NH2) was utilized to immobilize the detection second antibody (Ab2) to construct a "signal-on" responsive sandwich-type electrochemiluminescence immunoassay. Meanwhile, tripropylamine (TPA) acts as the co-reactant and provides a luminescence system for Ru(bpy)32+@UiO-66-NH2. The luminescence-functionalized MOFs showed excellent ECL activity owing to the tunable structure of MOFs. The remarkable enhancement in ECL intensity was obtained by the immunoreaction of antigen and antibody. Under the optimized conditions, the biosensor exhibited a detection limit of 0.0001 U mL-1 (S/N = 3) with a wide range from 0.001 to 50 U mL-1. The proposed ECL immunosensor was applicable for detecting human serum samples with a recovery of 99.83 ∼ 101 % (RSD < 5 %). This work demonstrates that the advantage of multifunctional MOFs could be applied to construct highly selective ECL immunosensor, and it may facilitate the diagnosis of breast cancer in clinics.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Estruturas Metalorgânicas , Compostos Organometálicos , Humanos , Molibdênio , Imunoensaio/métodos , Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Biomarcadores Tumorais , Compostos Organometálicos/química , Anticorpos , Medições Luminescentes/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção , Nanopartículas Metálicas/química
20.
Anal Sci ; 40(8): 1459-1473, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38900232

RESUMO

The main reason for the high mortality rate of non-small cell lung cancer is that patients are usually diagnosed at an advanced stage of the disease. Exosomes, small membrane vesicles secreted by normal cells or tumor cells, play a significant role in the progression of NSCLC. This study successfully optimized the preparation of artificial nanoenzymes self-coupling with horseradish peroxidase (IrO2NPs@HRP-AptCD63), without adding any ligand, demonstrating remarkable catalytic activity suitable for detecting the EGFR protein on the surface of NSCLC exosomes. When fused with the CD63 aptamer for identifying NSCLC exosomes, IrO2NPs@HRP showed enhanced catalytic activity in the 3,3',5,5'-tetramethylbenzidine-H2O2 oxidation-reduction system, thereby enhancing the colorimetric signal. This phenomenon can be distinguished by the naked eye and quantified using a UV-Vis spectrophotometer. Meanwhile, as the redox reaction occurs, the current signal of 3,3',5,5'-tetramethylbenzidine-H2O2, acting as an electrolyte, changes. The developed aptasensor generates dual-mode signal outputs, firstly, to visually assess the samples for their positive or negative status, and subsequently employ more in-depth electrochemical or colorimetric analysis methods for a detailed quantitative analysis of suspected positive samples. The detection limits of electrochemical analysis and colorimetric analysis were 0.9 × 103 particles/mL and 0.14 × 103 particles/mL, respectively. Compared with traditional biomarkers such as CA125, this method exhibits exceptional specificity, capable of simultaneously distinguishing serum exosomes of healthy volunteers, COPD patients, and NSCLC patients, promoting exosome detection in mouse models for tumor monitoring. Additionally, it elucidates the changes in EGFR protein expression on the surface of serum exosomes throughout the developmental trajectory.


Assuntos
Aptâmeros de Nucleotídeos , Carcinoma Pulmonar de Células não Pequenas , Exossomos , Peroxidase do Rábano Silvestre , Irídio , Neoplasias Pulmonares , Oxirredução , Exossomos/química , Exossomos/metabolismo , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Aptâmeros de Nucleotídeos/química , Irídio/química , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/metabolismo , Animais , Camundongos , Nanopartículas Metálicas/química , Técnicas Biossensoriais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA