Simultaneous determination of captopril and hydrochlorothiazide by time-resolved chemiluminescence with artificial neural network calibration

The combined use of chemometrics and chemiluminescence（CL）measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril（CPL）and hydrochlorothiazide（HCT）.The stopped-flow technique in a continuous-flow system was employed in this work in order to emphasize the kinetic differences between the two analytes in cerium（IV）-rhodamine 6G CL system.After the flow was stopped,an initial rise of CL signal was observed for HCT standards,while a direct decay of CL signal was obtained for CPL standards.The mixed CL signal was monitored and recorded on the whole process of continuous-flow/stopped-flow,and the obtained data were processed by the chemometric approach of artificial neural network.The relative prediction error（RPE）of CPL and HCT was 5.9% and 8.7%,respectively.The recoveries of CPL and HCT in tablets were found to fall in the range between 95% and 106%.The proposed method was successfully applied to the simultaneous determination of CPL and HCT in a compound pharmaceutical formulation.

Ultrafast carrier dynamics in GeSn thin film based on time-resolved terahertz spectroscopy

We measure the time-resolved terahertz spectroscopy of GeSn thin film and studied the ultrafast dynamics of its photo-generated carriers.The experimental results show that there are photo-generated carriers in GeSn under femtosecond laser excitation at 2500 nm,and its pump-induced photoconductivity can be explained by the Drude–Smith model.The carrier recombination process is mainly dominated by defect-assisted Auger processes and defect capture.The firstand second-order recombination rates are obtained by the rate equation fitting,which are(2.6±1.1)×10^(-2)ps^(-1)and(6.6±1.8)×10^(-19)cm^(3)·ps^(-1),respectively.Meanwhile,we also obtain the diffusion length of photo-generated carriers in GeSn,which is about 0.4μm,and it changes with the pump delay time.These results are important for the GeSn-based infrared optoelectronic devices,and demonstrate that Ge Sn materials can be applied to high-speed optoelectronic detectors and other applications.

Time-resolved K-shell x-ray spectra of nanosecond laser-produced titanium tracer in gold plasmas

A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e.,the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment–theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.

Clinical value of chemiluminescence method for detection of antinuclear antibody profiles

BACKGROUND Antinuclear antibodies(ANAs)are crucial in diagnosing autoimmune diseases,mainly systemic lupus erythematosus(SLE).This study aimed to compare the performance of chemiluminescence assay(CLIA)and line immunoassay(LIA)in detecting ANAs in patients with autoimmune diseases,evaluate their diagnostic accuracy for SLE,and develop a novel diagnostic model using CLIA-detected antibodies for SLE.Specimens from patients with autoimmune diseases and physical examination specimens were collected to parallel detect specific antibodies.Individual antibodies'diagnostic performance and a model combining multiple antibodies were assessed.The findings provide valuable insights into improving the diagnosis of SLE through innovative approaches.AIM To compare the performance of CLIA and LIA in detecting ANAs in patients with autoimmune diseases,assess their accuracy for SLE,and develop a novel diagnostic model using CLIA-detected antibodies for SLE.METHODS Specimens have been obtained from 270 patients with clinically diagnosed autoimmune disorders,as well as 130 physical examination specimens.After that,parallel detection of anti-double-stranded DNA(dsDNA)antibody,anti-histone(Histone)antibody,anti-nucleosome(Nuc)antibody,anti-Smith(Sm)antibody,anti-ribosomal P protein(Rib-P)antibody,anti-sicca syndrome A(Ro60)antibody,anti-sicca syndrome A(Ro52)antibody,anti-sicca syndrome(SSB)antibody,anticentromere protein B(Cenp-B)antibody,anti-DNA topoisomerase 1(Scl-70)antibody,anti-histidyl tRNA synthetase(Jo-1)antibody,and anti-mitochondrial M2(AMA-M2)antibody was performed using CLIA and LIA.The detection rates,compliance rates,and diagnostic performance for SLE were compared between the two methodologies,followed by developing a novel diagnostic model for SLE.RESULTS CLIA and LIA exhibited essentially comparable detection rates for anti-dsDNA antibody,anti-Histone antibody,anti-Nuc antibody,anti-Sm antibody,anti-Rib-P antibody,anti-Ro60 antibody,anti-Ro52 antibody,anti-SSB antibody,anti-Cenp-B antibody,anti-DNAScl-70 antibody,anti-Jo-1 antibody and anti-AMA-M2 antibody(P>0.05).The two methods displayed identical results for the detection of anti-dsDNA antibody,anti-Histone antibody,anti-Nuc antibody,anti-Sm antibody,anti-Ro60 antibody,anti-Ro52 antibody,anti-SSB antibody,anti-Cenp-B antibody,anti-Scl-70 antibody,and anti-AMA-M2 antibody(Kappa>0.7,P<0.05),but showed a moderate agreement for the detection of anti-Rib-P antibody and anti-Jo-1 antibody(Kappa=0.671 and 0.665;P<0.05).In addition,the diagnostic performance of these antibodies detected by both methods was similar for SLE.The diagnostic model's area under the curve values,sensitivity,and specificity,including an anti-dsDNA antibody and an anti-Ro60 antibody detected by CLIA,were 0.997,0.962,and 0.978,respectively.These values were higher than the diagnostic performance of individual antibodies.CONCLUSION CLIA and LIA demonstrated excellent overall consistency in detecting ANA profiles.A diagnostic model based on CLIA-detected antibodies can successfully contribute to developing a novel technique for detecting SLE.

New Time-resolved-Tween 80 Chemiluminescent System for Simultaneous Determination of Trace Gold and Osmium

A time resolved chemiluminescent analysis for simultaneous determination of trace Au(Ⅲ) and Os(Ⅳ) was proposed. The method is based on the kinetic distinction of Au(Ⅲ) and Os(Ⅳ) in Tween 80 KOH chemilumescent system. The detection limits were 1.1×10 -9 g/ml for Au(Ⅲ) and 1.0×10 -8 g/ml for Os(Ⅳ), with the linear ranges of 1.0×10 -8 ～1.0×10 -5 g/ml for Au(Ⅲ) and 1.0×10 -7 ～1.0×10 -6 g/ml for Os(Ⅳ). The method was applied to the determination of Au(Ⅲ) and Os(Ⅳ) in the sample of metallurgical materials of noble metals with satisfactory results.

Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that the unsaturated complex of Cu(II) and benzoic acid (1:1) has strong catalytic effect on the luminol-H2O2 chemiluminescence reaction. The calibration graph is linear over the range of 0.025 ~ 60 g/mL of benzoic acid, with a relative standard deviation of less than 3.0 %, and the detection limit is 0.01礸穖L-1. The proposed method was applied to the determination of benzoic acid content in different pharmaceutical formulations.

Chemiluminescence detection of permanganate index (COD_(Mn)) by a luminol-KMnO_4 based reaction

A novel chemiluminescence （CL） system for determination of permanganate index （CODMn） combined with flow injection analysis has been proposed in this study. On the basis of the chemiluminescent reaction of luminol-KMnO4 system, light emission caused by luminol-KMnO4 system was detected by the photomultiplier tube, and its intensity caused by the appearance of KMnO4 after sample digestion was inversely proportional to CODMn. Effects for CODMn determining such as pH, concentrations and interference were investigated in detail. A detection limit of 0.3 mg/L CODMn with a linear range of 0.3-200 mg/L for its theoretical CODMn was obtained under the optimized experimental conditions. The relative standard deviation was 4.3% for 5.0 mg/L CODMn （n = 11）. This CL flow system for determining CODMn was simple, rapid, and suitable for automatic analysis. The data obtained by the present method were fairly in good agreement with those obtained by the standard titrimetric method. It has been applied to determine real samples with satisfactory results.

Recent advances in electrogenerated chemiluminescence biosensing methods for pharmaceuticals

Electrogenerated chemiluminescence(electrochemiluminescence, ECL) generates species at electrode surfaces, which undergoes electron-transfer reactions and forms excited states to emit light. It has become a very powerful analytical technique and has been widely used in such as clinical testing, biowarfare agent detection, and pharmaceutical analysis. This review focuses on the current trends of molecular recognition-based biosensing methods for pharmaceutical analysis since 2010. It introduces a background of ECL and presents the recent ECL developments in ECL immunoassay(ECLIA), immunosensors, enzyme-based biosensors, aptamer-based biosensors, and molecularly imprinted polymers(MIP)-based sensors. At last, the future perspective for these analytical methods is briefly discussed.

Determination of resveratrol in red wine by solid phase extraction-flow injection chemiluminescence method

A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO4 and HCHO in sulfuric acid medium. Analytes were pre-concentrated on solid sorbents （C18 solid-phase extraction cartridges）. Under the optimum conditions, the proposed method allows the measurement of resveratrol over the range of 1.32 × 10^-8 to 1.32 × 10^-5 mol/L with a detection limit of 3.30 ×10^-9 mol/L, and the relative standard deviation for 1.32 ×10^-5 mol/L resveratrol （n = 11） is 3.8%. This method has been successfully applied for the determination of the resveratrol in red wine. Furthermore, the possible reaction mechanism was also discussed.

Chemiluminescence Determination of Molybdenum by on-Line Reduction with a Flow Injection System

The chemiluminescence (CL) reaction between lucigenin (Lu) and molybdenum (III) produced by a Jones reductor was investigated using a flow injection system. On the basis of this, a novel method for the determination of trace amount of molybdenum has been established. The emission intensity was linear with molybdenum concentration in the range of 0.1-1000 ng/mL; the detection limit was 0.02 ng/mL molybdenum; the relative standard deviation was less than 2% for the determination of 0.1 ng/mL molybdenum (n=11). The method has been applied successfully to the analysis of trace molybdenum in water and steel samples.

Solid Phase Extraction Chemiluminescence Determination of Methamidaphos on Vegetables

The determination of the methamidaphos pesticide residue on vegetables with a simple solid phase extract（SPE） flow injection（FI） -chemiluminescence（CL） method is described. The method is based on the enhancing effect of methamidaphos on the CL reaction of luminol with hydrogen peroxide in an alkaline solution. Under the optimal conditions, the CL intensity is linear to the methamidaphos mass concentration in a range of 0. 2-13μg/mL （ r= 0. 9992）. The detection limit（3σ） is 0. 047μg/mL. The relative standard deviations for the analysis of three samples are 1.8%, 2.5% and 3.7% （ n = 5 ）, respectively. The recovery is in a range of 90%-109% by the method. In this work, this method was successfully applied to the determination of the methamidaphos residue on some vegetable samples.

Highly sensitive chemiluminescence technology for protein detection using aptamer-based rolling circle amplification platform

A robust, selective and highly sensitive chemiluminescent （CL） platform for protein assay was presented in this paper. This novel CL approach utilized rolling circle amplification （RCA） as a signal enhancement technique and the 96-well plate as the immobilization and separation carrier. Typically, the antibody immobilized on the surface of 96-well plate was sandwiched with the protein target and the aptamer-primer sequence. This aptamer-primer sequence was then employed as the primer of RCA. Based on this design, a number of the biotinylated probes and streptavidin-horseradish peroxidase （SA-HRP） were captured on the plate, and the CL signal was amplified. In summary, our results demonstrated a robust biosensor with a detection limit of 10 fM that is easy to be established and utilized, and devoid of light source. Therefore, this new technique .will broaden the perspective for future development of DNA-based biosensors for the detection of other protein biomarkers related to clinical diseases, by taking advantages of high sensitivity and selectivity.

Diagnosis of Toxoplasma gondii infection in pregnant women using automated chemiluminescence and quantitative real time PCR

Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collected from pregnant women referred to the health care centers in Salmas city. The demographic variables were also recorded. Titers of antiToxoplasma IgM and IgG antibodies(Ab) were determined using the chemiluminescence immunoassay. Quantitative real-time PCR targeting the T. gondii repeated element gene was also performed on the blood sample. Results: Out of all, 19.92%(55/276) and 2.17%(6/276) patients were seropositive for anti-Toxoplasma IgG and IgM Ab, respectively. Moreover, the presence of T. gondii DNA was observed in 12.31%(34/276) blood samples. A significant relationship was observed between the IgG Ab seropositivity and contact with the cat as a risk factor(P=0.022). Conclusions: The seroprevalence rate of T. gondii infection in pregnant women is relatively low. Consequently, the seronegative pregnant women are at risk, and a considerable rate of positive blood samples for the presence of parasite's DNA should not be ignored. Besides, quantitative real-time PCR could be considered as an accurate method for diagnosis of acute toxoplasmosis especially when the precise results are of the most importance in pregnancy. Limiting contact with cats is also suggested for pregnant women.

Comparison of chemiluminescence enzyme immunoassay based on magnetic microparticles with traditional colorimetric ELISA for the detection of serum α-fetoprotein

A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).

Determination of Gossypol in Trace Level by Flow Injection Analysis with Chemiluminescence Detection

This work reports the single-molecule detection of gossypol by flow injection analysis with chemiluminescence method. The method is based on the reaction of luminol with ferricyanid in sodium hydroxide medium sensitized by gossypol. Under the optimum conditions, the CL intensity is proportional to the concentration of gossypol over the range of 1.11×10^-17-2.78×10^-16 mol/L in acid solution and 8.00×10^-11-7.39×10^-8mol/L in neutral solution with correlation coefficients 0.9983 and 0.9905, respectively. The detection limits is 1.60×10^-18 mol/L （S/N=3）. The proposed method has been applied for the determination of the gossypol in cottonseeds and pharmaceutical formulations with satisfactory results.

Study on superoxide and hydroxyl radicals generated in indirect electrochemical oxidation by chemiluminescence and UV-Visible spectra

The generation and transformation of radicals on the cathode of indirect electrochemical oxidation were studied by chemilumines- cence(CL)and UV-Visible spectra in the reactor with a salt bridge that connected the separated chambers.The CL intensity of 4×10^(-9)mol/L luminol on the cathode with bubbling oxygen was about seven times that of the intensity without it,which was because of the generation of reactive oxygen species(ROS).The existence of ROS,especially the generation of the superoxide radical,coul...

A Quantitative DNA Methylation Assay Using Mismatch Hybridization and Chemiluminescence

To develop a quantitative method for methylation analysis of the p16 gene based on mismatch hybridization and chemiluminescence. Methods Genomic DNA was modified by sodium bisulfite to convert all unmethylated but not methylated cytosines to uracil, and subsequently a pair of primer having no CpG sites was designed for amplification target DNA containing methylated or unmethylated CpG sites. The PCR product spanning CpG sites were hybridized with two oligonucleotide probes which perfectly matched the methylated and unmethylated CpG sequences respectively, and the hybrids were detected by chemiluminescent method. The percentage of methylated target sequences could be estimated by calculating the ratio of signals obtained with two probes. Results The percentage of methylation of artificial mixtures DNA showed a linear relation. There was a negative correlation between the methyaltion index with p16 transcriptional mRNA of p16 gene in tumor cell lines. Conclusion Compared with existing methods, this assay is nonisotopic, rapid, simple, and can be widely applied to the study of DNA methylation.

A novel method for Co(Ⅱ) and Cu(Ⅱ) analysis by capillary electrophoresis with chemiluminescence detection

Based on the fact that some metal ions can catalyze the chemiluminescence(CL)reaction of luminol with K_3Fe(CN)_6,a novel capillary electrophoresis CL method was developed for the determination of Co(Ⅱ)and Cu(Ⅱ).The separation was carried out with a 10 mmol/L sodium acetate solution containing 0.8 mmol/L luminol and 2.0 mmol/Lα-HIBA(adjusted to pH 4.8 by HAc solution).The post-capillary reagent was 2.0 mmol/L K_3Fe(CN)_6 which was adjusted to pH 13.0 by NaOH solution.Under the optimum conditions,the detection limits(S/N=3)for Co(Ⅱ)and Cu(Ⅱ)were 7.5×10^(-11)mol/L and 7.5×10^(-9)mol/L,with the linear range of 7.5×10^(-9)mol/L to 1.0×10^(-6)mol/L and 7.5×10^(-8)mol/L to 5.0×10^(-5)mol/L, respectively.

Flow injection chemiluminescence determination of loxoprofen and naproxen with the acidic permanganate-sulfite system

A novel flow injection chemiluminescence（CL）method for the determination of loxoprofen and naproxen was proposed based on the CL system of KMnO4 and Na2SO3 in acid media.The CL intensity of KMnO4-Na2SO3 was greatly enhanced in the presence of loxoprofen and naproxen.The mechanism of the CL reaction was studied by the kinetic process and UV-vis absorption and the conditions were optimized.Under optimized conditions,the CL intensity was linear with loxoprofen and naproxen concentration in the range of 7.0×10^-8-1.0×10^-5g/mL and 2.0×10^-7-4.0×10^-6g/mL with the detection limit of 2.0×10-8g/mL and 3.0×10-8g/mL（S/N=3）,respectively.The relative standard deviations were 2.39% and 1.37% for 5.0×10^-7g/mL naproxen and 5.0×10^-7g/mL loxoprofen（n=10）,respectively.The proposed method was satisfactorily applied to the determination of loxoprofen and naproxen in pharmaceutical preparations.

Flow-injection chemiluminescence determination of tryptophan using galangin-potassium permanganate-polyphosphoric acid system

A high sensitive flow-injection chemiluminescence （FI-CL） method for the determination of tryptophan has been developed. The method is based on the chemiluminescence reaction of galangin-potassium permanganate-tryptophan in polyphosphoric acid （PPA） media. Under the optimized conditions, tryptophan was determined in the range 0.05-10 μg/mL with the detection limit （3tr） of 5.0 × 10^-3 μg/mL. The relative standard deviation （RSD） was 1.0% for 11 replicate determinations of 1.0 μg/mL tryptophan. Three synthetic samples were determined selectively with recoveries in the range from 99.6% to 102.0% in the presence of other amino acids.