[Protective effect of breviscapine against brain injury induced by intrauterine inflammation in preterm rats and its mechanism]. / ç¯ç›èŠ±ç´ å¯¹å®«å† ç‚Žç—‡è‡´æ—©äº§å¤§é¼ è„‘æŸä¼¤çš„ä¿æŠ¤ä½œç”¨åŠå ¶æœºåˆ¶æŽ¢è®¨.

OBJECTIVES: To study the protective effect of breviscapine against brain injury induced by intrauterine inflammation in preterm rats and its mechanism. METHODS: A preterm rat model of brain injury caused by intrauterine inflammation was prepared by intraperitoneal injections of lipopolysaccharide in pregnant rats. The pregnant rats and preterm rats were respectively randomly divided into 5 groups: control, model, low-dose breviscapine (45 mg/kg), high-dose breviscapine (90 mg/kg), and high-dose breviscapine (90 mg/kg)+ML385 [a nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor, 30 mg/kg] (n=10 each). The number and body weight of the live offspring rats were measured for each group. Hematoxylin-eosin staining was used to observe the pathological morphology of the uterus and placenta of pregnant rats and the pathological morphology of the brain tissue of offspring rats. Immunofluorescent staining was used to measure the co-expression of ionized calcium binding adaptor molecule-1 (IBA-1) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) in the cerebral cortex of offspring rats. ELISA was used to measure the levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1ß (IL-1ß) in the brain tissue of offspring rats. Western blotting was used to measure the expression of Nrf2 pathway-related proteins in the brain tissue of offspring rats. RESULTS: Pathological injury was found in the uterus, and placenta tissue of the pregnant rats and the brain tissue of the offspring rats, and severe microglia pyroptosis occurred in the cerebral cortex of the offspring rats in the model group. Compared with the control group, the model group had significant reductions in the number and body weight of the live offspring rats and the protein expression levels of Nrf2 and heme oxygenase-1 (HO-1) in the brain tissue of the offspring rats (P<0.05), but significant increases in the relative fluorescence intensity of the co-expression of IBA-1 and NLRP3, the levels of the inflammatory factors IL-6, IL-8, and IL-1ß, and the protein expression levels of NLRP3 and caspase-1 in the brain tissue of the offspring rats (P<0.05). Compared with the model group, the breviscapine administration groups showed alleviated pathological injury of the uterus and placenta tissue of the pregnant rats and the brain tissue of the offspring rats, significant increases in the number and body weight of the live offspring rats and the protein expression levels of Nrf2 and HO-1 in the brain tissue of the offspring rats (P<0.05), and significant reductions in the relative fluorescence intensity of the co-expression of IBA-1 and NLRP3, the levels of the inflammatory factors IL-6, IL-8, and IL-1ß, and the protein expression levels of NLRP3 and caspase-1 in the brain tissue of the offspring rats (P<0.05). The high-dose breviscapine group had a significantly better effect than the low-dose breviscapine (P<0.05). ML385 significantly inhibited the intervention effect of high-dose breviscapine (P<0.05). CONCLUSIONS: Breviscapine can inhibit inflammatory response in brain tissue of preterm rats caused by intrauterine inflammation by activating the Nrf2 pathway, and it can also inhibit microglial pyroptosis and alleviate brain injury.

Cyanine dye-assembled composite upconversion nanoparticles for the sensing and cell imaging of nitrite based on a single particle imaging method.

In this work, a single particle imaging method based on the total internal reflection (TIR) imaging platform for the sensing and cell imaging of nitrite (NO2-) in the near-infrared region using cyanine dye-assembled composite upconversion nanoparticles (UCNPs) was developed. The NaYF4:Yb,Tm@NaGdF4 UCNPs were synthesized as energy donors, and the cyanine dye IR-798 was prepared as an energy acceptor. Since the absorption spectrum of the cyanine dye IR-798 and the luminescence spectrum of upconversion nanoparticles overlapped effectively, IR-798 quenched the luminescence of the UCNPs. When NO2- was added to the cyanine dye-assembled composite upconversion nanoparticle system, NO2- destroyed the conjugate structure of IR-798, so that the luminous intensity of UCNPs could be restored. Based on the mechanism, a quantitative image analysis with high sensitivity, low sample usage, and fast response time using the TIR single particle imaging platform was developed to determine the content of nitrite in human serum samples. In addition, the UCNPs-IR-798 probe was applied to image the exogenous NO2- content in HeLa living cells based on the single particle imaging platform.

A hybrid boronate affinity probe for the selective detection of cis-diol containing compounds in tea beverages.

UiO-66-NH2 nanocomposite was post-modified with 4-mercaptophenylboronic acid (MPBA) by the method of in situ hybridization reaction. The hybrid boronate affinity material UiO-NH2 @P (TEPIC-co-MPBA) was characterized by scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy. The material was applied as fluorescent probe for the detection of cis-diol containing compounds based on the boronate affinity mechanism, and exhibited high specific selectively. The proposed method exhibited good linearity for the detection of catechol in the range of 0.50 to 8.00 µg ml-1 . The detection limit was 0.13 µg ml-1 . The tactic was successfully applied to analyze the total polyphenols in tea beverages for catechol, and relative recovery was in 98.86-106.00%. Therefore, this work provided a promising strategy for the recognition of cis-diol containing compounds.

Sensitive detection of sulfide ions in red region based on luminescence resonance energy transfer between upconversion nanoparticles and dye-670.

Many sulfides are toxic substances that easily harm the respiratory tract, therefore affecting respiratory function or damaging other organs of the body, leading to its failure. Therefore, there is a pressing need to develop methods for sensitive detection of sulfur ions (S2- ). Based on luminescence resonance energy transfer (LRET) theory, we report the construction of a near-infrared (NIR) excitation luminescence probe using NaGdF4 :Yb3+ ,Er3+ @NaYF4 upconversion nanoparticles (UCNPs) as the donor and dye-670 as the receptor for detection of S2- . When UCNPs and dye-670 molecules were combined using ligand exchange and electrostatic attraction, LRET occurred and UCNP luminescence was quenched. When S2- was added to the system, sulfide ions were able to destroy the double bond of the dye, inhibiting LRET and restoring UCNP luminescence. Under optimum condition, the linear range of S2- detection was 0.65-18.2 µM, and the detection limit was 34.2 nM. This method was applied for determination of S2- in water with satisfactory results.

Turn-on detection of glutathione S-transferase based on luminescence resonance energy transfer between near-infrared to near-infrared core-shell upconversion nanoparticles and organic dye.

Glutathione S-transferase (GST) is a detoxification enzyme of the liver and kidney. Based on the toxicological effect of GST, it is of great significance to develop a rapid and sensitive detection method for GST. In this work, a new luminescence resonance energy transfer (LRET) system has been designed to detect glutathione S-transferase in the near-infrared (NIR) region by utilizing NaGdF4:Yb3+,Tm3+@NaYF4 upconversion nanoparticles (UCNPs) as the donor and NIR dye-806@Glutathione (IR806@GSH) as the acceptor. NaGdF4:Yb3+,Tm3+@NaYF4 UCNPs were synthesized by a coprecipitation method and surface modification of NOBF4. The donor (positively charged) interacted with the acceptor (negatively charged) via electrostatic interactions to bring them into close proximity; then, LRET occurred and the luminescence was quenched. In the presence of GST, GST can specifically interact with the GSH of IR806@GSH molecule, making IR806@GSH far away from the donor surface, inhibiting the LRET, and restoring the luminescence of the UCNPs. There was a good linear relationship between the luminescence recovery intensity of UCNPs and GST concentration, ranging from 0.11 to 14.19 nM, and the detection of limit was 0.06 nM. The method has been used in the detection of GST in human serum samples and is expected to have potential applications in the biological field. Graphical abstract A luminescence resonance energy transfer system was developed for determination of glutathione S-transferase in the near-infrared region by utilizing NaGdF4:Yb3+,Tm3+@NaYF4 upconversion nanoparticles as the donor and NIR dye-806@Glutathione as the acceptor.

Correction: Technology-Based Interventions in Oral Anticoagulation Management: Meta-Analysis of Randomized Controlled Trials.

[This corrects the article DOI: 10.2196/18386.].

Technology-Based Interventions in Oral Anticoagulation Management: Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: An increasing number of patients have received prophylactic or therapeutic oral anticoagulants (OACs) for thromboembolic complications of diseases. The use of OACs is associated with both clinical benefits and risks. Considering the challenges imposed by this class of drugs, as well as the enormous progress made in portable device technology, it is possible that technology-based interventions may improve clinical benefits for patients and optimize anticoagulation management. OBJECTIVE: This study was designed to comprehensively evaluate the role of technology-based interventions in the management of OACs. METHODS: We searched 6 databases-PubMed, EMBASE, Cochrane, Cumulative Index to Nursing and Allied Health Literature, Scopus, and PsycINFO-to retrieve relevant studies published as of November 1, 2019, to evaluate the effect of technology-based interventions on oral anticoagulation management. RevMan (version 5.3; Cochrane) software was used to evaluate and analyze clinical outcomes. The methodological quality of studies was assessed by the Cochrane risk of bias tool. RESULTS: A total of 15 randomized controlled trials (RCTs) were selected for analysis. They reported data for 2218 patients (1110 patients in the intervention groups and 1108 patients in the control groups). A meta-analysis was performed on the effectiveness and safety data reported in the RCTs. Technology-based interventions significantly improved the effectiveness of oral anticoagulation management (mean difference [MD]=6.07; 95% CI 0.84-11.30; I2=72%; P=.02). The safety of oral anticoagulation management was also improved, but the results were not statistically significant. Bleeding events were reduced (major bleeding events MD=1.02; 95% CI 0.78-1.32; I2=0%; P=.90; minor bleeding events MD=1.06, 95% CI 0.77-1.44; I2=41%; P=.73) and thromboembolism events were reduced (MD=0.71; 95% CI 0.49-1.01; I2=0%; P=.06). In general, patients were more satisfied with technology-based interventions, which could also improve their knowledge of anticoagulation management, improve their quality of life, and reduce mortality and hospitalization events. CONCLUSIONS: Using technology to manage OACs can improve the effectiveness and safety of oral anticoagulation management, result in higher patient satisfaction, and allow greater understanding of anticoagulation.

Prevalence and genotype distribution of human papillomavirus infection among women: A population-based study in Dali Bai Autonomous Prefecture, Yunnan Province, China.

Accumulating evidence indicates that persistent infection with high-risk oncogenic human papillomavirus (HPV) genotypes is the most important risk factor for cervical cancer, and that the distribution of HPV genotypes varies regionally. This study explored the prevalence and genotype distribution of HPV infection among Han, Yi, and Bai women in various regions of Dali Bai Autonomous Prefecture, Yunnan Province, China. This cross-sectional study included 2779 women (20-76 years old) who were referred for 21-HPV genotype array diagnostic from five regions of Dali Bai Autonomous Prefecture between February 2013 and May 2016. Statistical methods used included a the χ2 test, Fisher's exact test, t test, and logistic regression. Overall HPV prevalence in the study population was 7.6%. HPV-52, HPV-58, HPV-18, HPV-81, and HPV-16 were the most prevalent genotypes in the study area, and notably, the prevalence of HPV-58 was significantly higher among women in Heqing County than that in other regions. Univariate analysis showed that husband's age, region, fertility status, and parity were potential factors associated with HPV infection. Multivariate logistic regression analysis revealed that Heqing County was an independent risk factor for HPV infection among women in the Dali area, moreover, Yi women showed the highest risk for HPV infections. Overall, our finding emphasizing the urgent need for an HPV screening and prevention program in Heqing County and Yi women. We also suggest that HPV-related health education should be provided not only to women, but also to men, to reduce the risk of infection in women.

The antimicrobial photodynamic inactivation resistance of Candida albicans is modulated by the Hog1 pathway and the Cap1 transcription factor.

Candida albicans is the most important fungal pathogen afflicting humans, particularly immunocompromised patients. However, currently available antifungal drugs are limited and ineffective against drug-resistant strains. The development of new drugs or alternative therapeutic approaches to control fungal infections is urgent and necessary. Photodynamic inactivation (PDI) is a new promising therapy for eradicating microorganism infections through combining visible light, photosensitizers, and oxygen to generate reactive oxygen species (ROS). Although cytoprotective responses induced by photodynamic therapy (PDT) have been well studied in cancer cells, the mechanisms by which C. albicans responds to PDI are largely unknown. In this study, we first demonstrated that PDI induces C. albicans Hog1p activation. Deletion of any of the SSK2, PBS2, and HOG1 genes significantly decreased the survival rate after photochemical reactions, indicating that the Hog1 SAPK pathway is required for tolerance to PDI. Furthermore, the basic leucine zipper transcription factor Cap1 that regulates several downstream antioxidant genes was highly expressed during the response to PDI, and loss of CAP1 also resulted in decreased C. albicans survival rates. This study demonstrates the importance of the Hog1 SAPK and the Cap1 transcription factor, which regulates in resistance to PDI-mediated oxidative stress in C. albicans. Understanding the mechanisms by which C. albicans responds to PDI and consequently scavenges ROS will be very useful for the further development of therapeutics to control fungal infectious diseases, particularly those of the skin and mucosal infections.

Construction of an upconversion luminescence composite nanoprobe for ratiometric single particle imaging detection of hydrogen peroxide in food.

Hydrogen peroxide (H2O2) is associated with diseases and food safety. Thus, it is essential to achieve sensitive and efficient detection of H2O2. Herein, a ratiometric luminescence composite nanoprobe was designed for single particle imaging sensing of H2O2 by combining NaYbF4:Er@NaYbF4:Tm@NaGdF4:Yb upconversion nanoparticles (UCNPs) with cyanine dye IR-628. High brightness NaYbF4:Er@NaYbF4:Tm@NaGdF4:Yb UCNPs with double-peak emission (665 and 812 nm) were synthesised. Cyanine dye IR-628 with an absorption peak at 628 nm was synthesised and served as a recognition unit. More importantly, on the basis of the upconversion luminescence total internal reflection imaging technique, we developed a ratiometric single particle imaging quantitative analysis for sensing H2O2 with a limit of quantitation of 5 nM. This ratiometric single particle imaging method not only greatly eliminates the influence of the probe concentration and instrumental and environmental factors, but also reduces the dosage of the reagent used and improves the sensitivity of detection.

Fine-tuning the specificity of boronate affinity monoliths toward glycoproteins through pH manipulation.

Boronate affinity functionalized materials have recently drawn increasing attention due to their capability to selectively isolate and enrich glycoproteins and glycopeptides. As cheaper and more stable competitors to lectins, boronic acids are generally believed to yield a relatively wider spectrum specificity to glycoproteins. For better understanding and effective utilization of boronate affinity, it is necessary to establish if boronic acids exhibit lectin-like narrow specificity towards individual or a sub-class of glycoproteins. Here we report a pH manipulation strategy for fine-tuning the specificity of boronate affinity monoliths towards two sub-classes of glycoproteins, sialylated and nonsialylated glycoproteins. When the binding pH > the pK(a) of the boronic acid by one pH unit or more, the boronate affinity monolith preferentially binds to glycoproteins containing neutral sugars and excludes sialic acid containing glycoproteins due to electrostatic repulsion. When the binding pH < the pK(a) by one pH unit or more, the boronate affinity monolith binds to sialylated glycoproteins due to the exceptional binding affinity of the boronic acid towards sialic acid residues. The alternative specificity towards sialic acid and neutral sugar was first verified using an off-line combination of boronate affinity extraction with nano-ESI-Orbitrap MS/MS detection. The alternative specificity towards sialylated and nonsialylated glycoproteins was then demonstrated by means of off-line combination of boronate affinity extraction with MALDI-TOF MS. Finally, the developed approach was applied to the alternative extraction of intact sialylated and nonsialylated glycoproteins spiked in human serum.

A facile method for fabricating TiO2@mesoporous carbon and three-layered nanocomposites.

Herein, we report a new and facile method for fabricating TiO(2)@mesoporous carbon hybrid materials. Uniform polydopamine (PDA) layers were coated onto the surface of titanate nanotubes (TNTs) and TiO(2) nanorods (TNDs) through the spontaneous adhesion and self-polymerization of dopamine during the dipping process. Core-shell mesoporous carbon nanotubes with TiO(2) nanorods or nanoparticles encapsulated inside (TiO(2)@MC) were then obtained by transforming PDA layers into carbonaceous ones through calcination in nitrogen at 800 °C. The thickness of the mesoporous carbon layers is tens of nanometers and can be controlled by adjusting the coated PDA layers through the self-polymerization reaction time. In addition, three-layered nanocomposites of TiO(2)@MC@MO (MO, metal oxide) can be readily prepared by utilizing PDA layers in TNTs@PDA or TNDs@PDA to adsorb the metal ions, followed by the calcination process.

Improvement of Aerosol Filtering Performance of PLLA/PAN Composite Fiber with Gradient Structure.

Since commercial non-woven air filtering materials have unstable filtering efficiency and poor moisture permeability for the abundant condensed aerosol particles in the highly humid atmospheric environment, the PLLA/PAN composite fiber material with a hydrophobic and hydrophilic gradient structure is designed and prepared by using electrode sputtering electro spinning technology. By characterizing and testing the filtrating effect of SEM, XRD, FTIR, wettability, mechanical property, N2 adsorption isotherm, and BET surface area, NaCl aerosol of PLLA fiber, PAN fiber, and PLLA/PAN composite fiber membranes, the study found that the electrode sputtering electrospinning is fine, the fiber mesh is dense, and fiber distribution is uniform when the diameter of the PAN fiber is 140-300 nm, and the PLLA fiber is 700-850 nm. In this case, PLLA/PAN composite fiber materials gather the hydrophobicity of PLLA fiber and the hydrophilicity of PAN fiber; its electrostatic effect is stable, its physical capturing performance is excellent, it can realize the step filtration of gas-solid liquid multiphase flow to avoid the rapid increase of air resistance in a high-humidity environment, and the filtrating efficiency η of NaCl aerosol particles with 0.3 µm reaches 99.98%, and the quality factor QF 0.0968 Pa-1. The manufacturing of PLLA/PAN composite fiber material provides a new method for designing and developing high-performance air filtration materials and a new technical means for the large-scale production of high-performance, high-stability, and low-cost polylactic acid nanofiber composites.

Quantitative image analysis method for detection of nitrite with cyanine dye-NaYF4:Yb,Tm@NaYF4 upconversion nanoparticles composite luminescent probe.

In this work, a quantitative image analysis method based on cyanine dye-upconversion nanoparticles composite luminescent nanoprobe for the detection of nitrite was developed. The nanoprobe was constructed by combining the NaYF4:Yb,Tm@NaYF4 upconversion nanoparticles (UCNPs) and the new cyanine dye IR-790. The upconversion nanoparticles transferred energy to IR-790, resulting in the luminescence quenching, while the luminescence of UCNPs was recovered after adding NO2-. The increase in photons was related to the concentration of NO2-. Under the optimal experimental conditions, the detection range was 0.20-140 µM and the limit of detection was 0.030 µM. The measurement for NO2- can be completed in 29 min. The method has the characteristics of fast response (~0.1 s), low sample consumption (10 µL) and powerful data support (550 frame time series images). Furthermore, the quantitative image analysis method was successfully applied for the analysis of nitrite in environmental water and food samples.

Prevalence and Genetic Analysis of ß-Thalassemia in the Dali Bai Autonomous Prefecture of the Yunnan Province, China.

Background: ß-Thalassemia is the most common monogenetic hemolytic hemoglobin-associated disease in the south of China; the distribution of genetic mutations associated with this condition varies according to geographic regions. This study investigated the prevalence and distribution of ß-thalassemia-associated mutations across different ethnic groups in the Dali Bai Autonomous Prefecture of the Yunnan Province, China. Methods: This cross-sectional study included 4723 participants (15-45 years old) who volunteered for thalassaemia screening from the Dali Bai Autonomous Prefecture from May 2017 to October 2020. Cellulose acetate membrane electrophoresis was used to screen for ß-thalassemia carriers. Genotypic analyses was performed using polymerase chain reaction-based reverse dot blotting and DNA sequencing. Results: The overall prevalence of ß-thalassemia in the study population was 2.01%. The genotypic analyses showed the presence of four types of mutations in the ß-globin gene: CD26 (GAG→AAG), CD56 (GGC→GAC), IVS-II-81 (C→T), and CD121 (GAA→CAA). In contrast to previous studies from other regions of Yunnan Province, our results showed that the prevalence of CD26 mutations was significantly higher than that of the other mutations. Conclusion: Our data suggests that the Dali Autonomous Prefecture is an area with a high prevalence of ß-thalassemia. Moreover, CD26 was the only ß-thalassemia mutation that we have detected. Moreover, the vast majority of the ß-thalassemia mutations observed were CD26.

An amperometric horseradish peroxidase inhibition biosensor for the determination of phenylhydrazine.

An amperometric horseradish peroxidase (HRP) inhibition biosensor has been substantially constructed by the help of N,N-dicyclohexylcarbodiimide (DCC), N-hydroxysuccinimide (NHS). The preparation steps and the biosensor response to phenylhydrazine were monitored by electrochemical impedance spectroscopy (EIS), cyclic voltammetry, and chronoamperometry. The proposed biosensor could be applied to determine phenylhydrazine in a 0.10 M phosphate buffer solution containing 1.2 mM hydroquinone and 0.50 mM H(2)O(2) by phenylhydrazine, inhibiting the catalytic activity of the HRP enzyme in the reduction of H(2)O(2). The system was optimized to realize a reliable determination of phenylhydrazine in the range of 2.5 x 10(-7) to 1.1 x 10(-6) M with a detection limit of 8.2 x 10(-8) M and a correlation coefficient of 0.999. The modified electrode displayed good reproducibility, sensitivity and stability for the determination of phenylhydrazine.

Voltammetric Behavior of o-Nitrophenol and Damage to DNA.

The electrochemical behavior of o-nitrophenol was studied in detail with a glassy carbon electrode (GCE). The dependence of peak potential on pH indicated that equivalent electrons and protons were involved in the process of o-nitrophenol reduction. The interaction of o-nitrophenol with calf thymus DNA was investigated by adding DNA to the o-nitrophenol solution and by immobilizing DNA on GCE, respectively. The peak current decrement and peak potential shift in presence of DNA indicated that o-nitrophenol could interact with DNA. The result was demonstrated that the in situ DNA damage was detected by differential pulse voltammetry after the o-nitrophenol was electrochemically reduced.

Direct electrochemistry behavior of cytochrome c/L-cysteine modified electrode and its electrocatalytic oxidation to nitric oxide.

Cytochrome c (Cyt c) was successfully immobilized on L-cysteine modified gold electrode by multicyclic voltammetry method. The electrochemical behavior of Cyt c on the L-cysteine modified electrode was explored. In 0.10 M, pH 7.0 phosphate buffer solution (PBS), Cyt c showed a quasi-reversible electrochemical redox behavior with E(pc)=0.180 V, E(pa)=0.208 V (versus Ag/AgCl). The Cyt c/L-cysteine modified electrode gave an excellent electrocatalytic activity towards the oxidation of nitric oxide, and the catalysis currents were proportional to the nitric oxide concentration in the range of 7.0 x 10(-7) to 1.0 x 10(-5) M, the linear regression equation is I (microA)=-0.124-0.003 C(NO) (microM), with a correlation coefficient 0.996, The detection limit was 3.0 x 10(-7) M (times the ratio of signal to noise, S/N=3).

Electrochemical determination of trace promethazine hydrochloride by a pretreated glassy carbon electrode modified with DNA.

A highly sensitive electrochemical biosensor for the detection of trace amounts of promethazine has been designed. Double stranded (ds)DNA molecules are immobilized onto a pretreated glassy carbon electrode (GCE(ox)) surface. The voltammetric behaviors of promethazine on DNA-modified electrode were explored by means of cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The promethazine gave rise to a pair of well-defined peaks, which appeared at E(pc) = 52 mV and E(pa) = 96 mV (vs. Ag/AgCl) in 0.10 M acetate buffer (pH 5.0). The peak current was linearly enhanced with increasing the concentration of promethazine. The calibration was linear for promethazine over the range of 4.7 x 10(-10) to 9.3 x 10(-9) M with a correlation coefficient of 0.999. The limit of detection (LODs) was 3.0 x 10(-10) M (S/N = 3). The modified electrode was applied to determine promethazine in human blood samples with satisfactory results.

Selective response of dopamine in the presence of ascorbic acid on L-cysteine self-assembled gold electrode.

A L-cysteine (L-Cys) self-assembled modified gold electrode was used to detect dopamine (DA) by chronoamperometric method (CE) in the presence of ascorbic acid (AA). The defective limit is 2.0 x 10(-8) mol L(-1) (S/N=3). The proposed method was applied to detect DA in the samples with satisfied result.