The Experts below are selected from a list of 3195 Experts worldwide ranked by ideXlab platform
Hua Cui - One of the best experts on this subject based on the ideXlab platform.
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Lucigenin co tryptophan 2 complex bifunctionalized graphene oxide facile synthesis and unique chemiluminescence
Journal of Materials Chemistry C, 2016Co-Authors: Wen Shen, Xiangyang Liu, Hua CuiAbstract:In this manuscript, Lucigenin (Luc) and Co2+ complex bifunctionalized graphene oxide hybrids (Co(Trp)2/Luc/GO) were synthesized via a facile and simple strategy by virtue of π–π stacking and electrostatic interaction. The as-prepared Co(Trp)2/Luc/GO hybrids exhibited good stability, water-solubility and excellent CL activity when reacted with H2O2, which was more than 30 times higher than Luc/GO. The CL mechanism between Co(Trp)2/Luc/GO and H2O2 has been proposed to be due to the fact that Co2+ could facilitate the formation of HO˙, O2˙− and Co2+–HO2−, accelerating Lucigenin CL reaction. Moreover, it was also found that ascorbic acid could directly react with Co(Trp)2/Luc/GO to generate CL emission in the presence of dissolved oxygen. By virtue of Co(Trp)2/Luc/GO as a platform, a sensitive, selective, reagent-less and disposable CL sensor for the detection of ascorbic acid was developed. Ascorbic acid could be determined in the range of 5.0 × 10−7–1.0 × 10−3 M with a detection limit of 0.4 μM. This work reveals that catalyst Co(Trp)2 assembled on the surface of Luc/GO exhibits a unique catalytic effect on Lucigenin CL reaction, which provides a new strategy for the synthesis of a Lucigenin functionalized nanomaterial with high CL efficiency. The synthesized Co(Trp)2/Luc/GO may find more applications in the development of novel analytical methods.
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a general strategy to prepare homogeneous and reagentless go Lucigenin enzyme biosensors for detection of small biomolecules
Biosensors and Bioelectronics, 2014Co-Authors: Lingfeng Gao, Hongli Zhang, Hua CuiAbstract:Abstract In this work, a novel biosensor was developed for the detection of glucose based on glucose oxidase (GOD) functionalized graphene oxide (GO)/Lucigenin nanocomposite. In this sensing strategy, GO/Lucigenin composite was first prepared by vigorously stirring GO with Lucigenin. Then the functionalization of GOD was achieved by simply storing GOD with GO/Lucigenin at 4 °C overnight to form GO/Lucigenin&GOD composite. When glucose was incubated with GO/Lucigenin&GOD composite for 50 min to generate H 2 O 2 , followed by the injection of 0.2 M NaOH, CL signal was detected due to the reaction of Lucigenin with H 2 O 2 . Glucose could be determined in the range of 1.0×10 −6 –5.0×10 −3 g mL −1 with a detection limit of 9.9×10 −7 g mL −1 . The present biosensor has been successfully applied for the detection of glucose in human serum samples. Compared with previously reported methods, this sensing strategy is homogeneous and reagentless and avoids complicated assembly procedure and pretreatment of serum sample, showing good stability, repeatability, high selectivity and simplicity. Moreover, this strategy has been demonstrated to be a general strategy by replacing GOD with other enzymes such as uricase and choline oxidase for the detection of small molecules such as uric acid and choline. The proposed biosensors may find future applications in the fields such as disease diagnosis and biomedicine.
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label free and homogeneous histone sensing based on chemiluminescence resonance energy transfer between Lucigenin and gold nanoparticles
Analytical Abstracts, 2013Co-Authors: Hua CuiAbstract:In this paper, a label free and homogeneous protocol without recognition elements such as antibody or DNA based on nonenzymatic chemiluminescence resonance energy transfer between Lucigenin and gold nanoparticles (AuNPs) is developed for the detection of histone. This chemiluminescence resonance energy transfer process originated from a chemiluminescent donor-acceptor pair in which the chemiluminescence system of the Lucigenin-H2O2 as a donor and AuNPs as an acceptor owing to the overlapping of the chemiluminescence spectrum of the Lucigenin-H2O2 system and the absorption spectrum of AuNPs, leading to a significant decrease in chemiluminescence signal from the Lucigenin-H2O2 system. However, the presence of histone resulted in the aggregation of AuNPs via the electrostatic interaction between negatively charged AuNPs and positively charged histone, which inhibited the chemiluminescence resonance energy transfer process. Thus the chemiluminescence signal of the Lucigenin-H2O2 system was restored. This could be used for the detection of histone with a linear range of 30-500 ng/mL, and a detection limit of 25 ng/mL. This sensitivity increased about 4 orders of magnitude over that of the reported fluorometric method. The proposed strategy for the detection of histone is simple, facile, reliable, and opens a new avenue for the determination of histone.
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fabrication of luminol and Lucigenin bifunctionalized gold nnanoparticles graphene oxide nanocomposites with dual wavelength chemiluminescence
Journal of Physical Chemistry C, 2012Co-Authors: Hua CuiAbstract:A facile, fast, and reliable method was proposed to prepare luminol and Lucigenin bifunctionalized AuNPs/GO nanocomposites via absorption of AuCl4– by positively charged Lucigenin functionalized GO and the subsequent reduction of AuCl4– by luminol at room temperature for the first time. The morphology and surface composition of the nanocomposites were characterized by transmission electron microscopy, X-ray powder diffraction, and mass and fluorescence spectra. The results indicated that AuNPs with a uniform size are fairly well monodispersed on the surface of GO. The size of AuNPs in the nanocomposites was tunable from 8 to 18 nm by changing the amount of AuCl4–. Moreover, it was found that luminol and Lucigenin coexisted on the surface of the nanocomposites. A formation mechanism of AuNPs/GO nanocomposites is proposed. It is suggested that Lucigenin molecules and AuNPs were located at the surface of GO by π–π stacking and electrostatic force respectively, and luminol existed on the surface of AuNPs by v...
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synthesis of dendritic platinum nanoparticles Lucigenin reduced graphene oxide hybrid with chemiluminescence activity
Chemistry: A European Journal, 2012Co-Authors: Hua CuiAbstract:Multifunctional hybrid: A dendritic platinum nanoparticle/Lucigenin/reduced graphene oxide (RGO) hybrid with chemiluminescence (CL) activity was prepared for the first time by using Lucigenin as a linker through simultaneous reduction of H(2) PtCl(4) and a Lucigenin-functionalized graphene oxide composite by sodium borohydride (see scheme). The hybrid may have potential applications as a CL sensor, in catalysis, energy conversion, and opto-electronic systems.
John R Aitken - One of the best experts on this subject based on the ideXlab platform.
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identification of cytochrome b5 reductase as the enzyme responsible for nadh dependent Lucigenin chemiluminescence in human spermatozoa
Biology of Reproduction, 2005Co-Authors: Mark A Baker, Anton Krutskikh, Benjamin J Curry, Louise Hetherington, John R AitkenAbstract:Lucigenin-dependent chemiluminescence together with 2-[4iodophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H tetrazolium monosodium salt (WST-1) reduction can be detected following addition of NADH to many cell types, including human sperm suspensions. Although many reports suggest that such a phenomenon is due to reactive oxygen species production, other oxygen detecting metabolite probes, such as MCLA and luminol, do not produce a chemiluminescent signal in this model system. The enzyme responsible for NADH-dependent Lucigenin chemiluminescence was purified and identified as cytochrome-b5 reductase. In support of this concept, COS-7 cells overexpressing cytochrome-b5 reductase displayed at least a 3-fold increase in the previously mentioned activity compared with mock-transfected cells. Fractions containing cytochrome-b5 reductase were capable of inducing both Lucigenin-dependent chemiluminescence and WST-1 reduction. Oxygen radicals clearly did not mediate the cytochrome b5-mediated activation of these probes in vitro since neither luminol nor MCLA gave a chemiluminescence response in the presence of the enzyme and the cofactor NADH. These results emphasize the importance of the direct NADHdependent reduction of these putative superoxide-sensitive probes by cytochrome-b5 reductase even though this enzyme does not, on its own accord, produce reactive oxygen species. cytochrome-b5 reductase, female reproductive tract, Lucigenin, reactive oxygen species, sperm, sperm capacitation, sperm maturation, spermatozoa, WST-1
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identification of cytochrome b5 reductase as the enzyme responsible for nadh dependent Lucigenin chemiluminescence in human spermatozoa
Biology of Reproduction, 2005Co-Authors: Mark A Baker, Anton Krutskikh, Benjamin J Curry, Louise Hetherington, John R AitkenAbstract:Lucigenin-dependent chemiluminescence together with 2-[4-iodophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H tetrazolium monosodium salt (WST-1) reduction can be detected following addition of NADH to many cell types, including human sperm suspensions. Although many reports suggest that such a phenomenon is due to reactive oxygen species production, other oxygen detecting metabolite probes, such as MCLA and luminol, do not produce a chemiluminescent signal in this model system. The enzyme responsible for NADH-dependent Lucigenin chemiluminescence was purified and identified as cytochrome-b5 reductase. In support of this concept, COS-7 cells overexpressing cytochrome-b5 reductase displayed at least a 3-fold increase in the previously mentioned activity compared with mock-transfected cells. Fractions containing cytochrome-b5 reductase were capable of inducing both Lucigenin-dependent chemiluminescence and WST-1 reduction. Oxygen radicals clearly did not mediate the cytochrome b5-mediated activation of these probes in vitro since neither luminol nor MCLA gave a chemiluminescence response in the presence of the enzyme and the cofactor NADH. These results emphasize the importance of the direct NADH-dependent reduction of these putative superoxide-sensitive probes by cytochrome-b5 reductase even though this enzyme does not, on its own accord, produce reactive oxygen species.
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identification of cytochrome p450 reductase as the enzyme responsible for nadph dependent Lucigenin and tetrazolium salt reduction in rat epididymal sperm preparations
Biology of Reproduction, 2004Co-Authors: Mark Baker, Anton Krutskikh, Benjamin J Curry, Eileen A Mclaughlin, John R AitkenAbstract:Lucigenin-dependent chemiluminescence and WST-1 reduction can be detected following addition of NADPH to many cell types, including rat epididymal sperm suspensions. Although many reports suggest that such a phenomenon is due to reactive oxygen species production, other probes-such as MCLA and luminol-that are capable of detecting reactive oxygen metabolites do not produce a chemiluminescent signal in this model system. Our aim was to purify and identify the enzyme catalyzing the NADPH-dependent Lucigenin and WST-1 reduction from rat epididymal spermatozoa preparations. Here, we show the identity of this enzyme as cytochrome P450-reductase. In support of this, a homogenous preparation of this protein was capable of reducing Lucigenin and WST-1 in the presence of NADPH. Moreover, COS-7 cells overexpressing cytochrome P450-reductase displayed a 3-fold increase in the aforementioned activity compared with mock-transfected cells. Immunolocalization studies and biochemical analysis suggest that the majority of the NADPH-Lucigenin activity is localized to the epithelial cells present within the epididymis. These results emphasize the importance of the direct NADPH-dependent reduction of superoxide-sensitive probes by cytochrome P450-reductase even though this enzyme does not, on its own accord, produce reactive oxygen species.
Michael A Trush - One of the best experts on this subject based on the ideXlab platform.
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biochemical characterization of Lucigenin bis n methylacridinium as a chemiluminescent probe for detecting intramitochondrial superoxide anion radical production
Biochemical and Biophysical Research Communications, 1999Co-Authors: Kevin H Stansbury, Hong Zhu, Michael A TrushAbstract:Direct detection of intramitochondrial superoxide anion radical (O−•2) production is of critical importance for investigating the pathophysiological consequences resulting from altered cellular reactive oxygen homeostasis. The purpose of this study with isolated mitochondria was to characterize the biochemical basis for Lucigenin as a chemiluminescent probe to detect intramitochondrial O−•2 production. Incubation of isolated mitochondria with Lucigenin at non-redox cycling concentration produced Lucigenin-derived chemiluminescence (LDCL), which was increased markedly by mitochondrial substrates, pyruvate/malate or succinate. The LDCL was reduced greatly by the membrane permeable superoxide dismutase (SOD) mimetics, 2,2,6,6-tetramethylpiperidine-N-oxyl and Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin, but not by Cu,Zn-SOD. With an ion-pair HPLC method, a concentration-dependent accumulation of Lucigenin was detected within mitochondria. The accumulation of Lucigenin by mitochondria was reduced markedly in the presence of carbonyl cyanide p-(trifluoromethoxy)phenyhyldrazone, an uncoupler known to dissipate the mitochondrial membrane potential. With submitochondrial particles, we observed that both complexes I and III of the mitochondrial electron transport chain appear to be able to catalyze the one electron reduction of Lucigenin, a critical step involved in LDCL. After incubation of mitochondria with Lucigenin at non-redox cycling concentrations, formation of N-methylacridone, the proposed end product of the reaction pathway leading to LDCL, within the mitochondrial fraction was also detected. In addition, a significant linear correlation was observed between the LDCL and either the Lucigenin accumulation or the N-methylacridone formation within the mitochondria. Taken together, our results conclusively demonstrate that when properly used LDCL can reliably detect intramitochondrial O−•2 production.
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detection of mitochondria derived reactive oxygen species production by the chemilumigenic probes Lucigenin and luminol
Biochimica et Biophysica Acta, 1999Co-Authors: Hong Zhu, Michael A TrushAbstract:Both Lucigenin and luminol have widely been used as chemilumigenic probes for detecting reactive oxygen species (ROS) production by various cellular systems. Our laboratory has previously demonstrated that Lucigenin localizes to the mitochondria of rat alveolar macrophages and that Lucigenin-derived chemiluminescence (CL) appears to reflects superoxide O2(-.) production by mitochondria in the unstimulated macrophages. In this study, we further examined the ability of Lucigenin- and luminol-derived CL to assess O2(-.) and H2O2 formation, respectively, by isolated intact mitochondria. Mitochondria were isolated from monocytes/macrophages differentiated from monoblastic ML-1 cells. Incubation of the substrate-supported mitochondria with Lucigenin at non-redox cycling concentration produced Lucigenin-derived CL. Luminol-derived CL was also elicited with substrate-supplemented mitochondria in the presence of horseradish peroxidase (HRP). The Lucigenin-derived CL was diminished extensively by the membrane permeable superoxide dismutase (SOD) mimetics, 2,2,6, 6-tetramethylpiperidine-N-oxyl and Mn(III) tetrakis(1-methyl-4-pyridyl)porphyrin, but not by Cu,Zn-SOD. On the other hand, luminol-derived CL was not observed in the absence of HRP and was significantly inhibited by catalase. A spectrum of agents known to specifically affect mitochondrial respiration exhibited corresponding effects on both Lucigenin- and luminol-derived CL. Taken together, our results demonstrate that with isolated mitochondria Lucigenin-derived CL monitors intramitochondrial O2(-.) production by the mitochondrial electron transport chain, whereas the luminol-derived CL detects H2O2 released from the mitochondria. As such, use of both probes provides a comprehensive and clear assessment of ROS production by mitochondria.
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validation of Lucigenin bis n methylacridinium as a chemilumigenic probe for detecting superoxide anion radical production by enzymatic and cellular systems
Journal of Biological Chemistry, 1998Co-Authors: Hong Zhu, Jay L Zweier, Periannan Kuppusamy, Valerie Roubaud, Michael A TrushAbstract:Lucigenin is most noted for its wide use as a chemiluminescent detector of superoxide anion radical (O2-.) production by biological systems. However, its validity as a O2-.-detecting probe has recently been questioned in view of its ability to undergo redox cycling in several in vitro enzymatic systems, which produce little or no O2-.. Whether and to what extent Lucigenin redox cycling occurs in systems that produce significant amounts of O2-. has not been carefully investigated. We examined and correlated three end points, including sensitive measurement of Lucigenin-derived chemiluminescence (LDCL), O2 consumption by oxygen polarography, and O2-. production by 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide spin trapping to characterize the potential of Lucigenin to undergo redox cycling and as such to act as an additional source of O2-. in various enzymatic and cellular systems. Marked LDCL was elicited at Lucigenin concentrations ranging from 1 to 5 microM in all of the O2-.-generating systems examined, including xanthine oxidase (XO)/xanthine, lipoamide dehydrogenase/ NADH, isolated mitochondria, mitochondria in intact cells, and phagocytic NADPH oxidase. These concentrations of Lucigenin were far below those that stimulated additional O2 consumption or O2-. production in the above systems. Moreover, a significant linear correlation between LDCL and superoxide dismutase-inhibitable cytochrome c reduction was observed in the XO/ xanthine and phagocytic NADPH oxidase systems. In contrast to the above O2-.-generating systems, no LDCL was observed at non-redox cycling concentrations of Lucigenin in the glucose oxidase/glucose and XO/NADH systems, which do not produce a significant amount of O2-.. Thus, LDCL still appears to be a valid probe for detecting O2-. production by enzymatic and cellular sources.
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further evidence that Lucigenin derived chemiluminescence monitors mitochondrial superoxide generation in rat alveolar macrophages
Free Radical Biology and Medicine, 1994Co-Authors: Stephen J Rembish, Michael A TrushAbstract:Abstract Lucigenin is well recognized for its ability to react with superoxide, yielding a product that emits chemiluminescence. Accordingly, Lucigenin-derived chemiluminescence (LDCL) has been widely used to assess the generation of superoxide by the NADPH oxidase of leukocytes. Previously, we suggested that Lucigenin could interact with mitochondrial-derived superoxide in alveolar macrophages. The purpose of this study was to further demonstrate that LDCL is in fact a probe of mitochondrial superoxide generation. Using fluorescence microscopy, we have observed that Lucigenin accumulates at the mitochondria of alveolar macrophages and exhibits a localization similar to that of rhodamine 123, a fluorescent indicator of mitochondrial membrane potential. We have also compared the effects of a spectrum of agents known to modulate mitochondrial respiration on both LDCL and cellular oxygen consumption. The agents examined included a Complex I inhibitor, rotenone; a Complex III inhibitor, antimycin a; and a Complex IV inhibitor, KCN. While these compound all inhibited oxygen consumption, only those that exert an effect prior to (rotenone) or at (antimycin a) the point of mitochondrial superoxide formation inhibited LDCL. KCN exhibits effects that are concetration dependent. At low concentrations (1–100 μM), a slight enhancement of LDCL is observed, while at higher concentrations (1–10 mM) both LDCL and oxygen consumption are inhibited. The ATP synthase inhibitor, oligomycin, was also observed to correspondingly inhibit oxygen consumption and LDCL. These inhibitor studies, taken together with the observation that Lucigenin localizes to the mitochondria of alveolar macrophages, provides strong evidence that LDCL can be used to qualitatively asses the modulation of mitochondrial superoxide generation in mononuclear cells.
Yongping Dong - One of the best experts on this subject based on the ideXlab platform.
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electrogenerated chemiluminescence resonance energy transfer between Lucigenin and cdse quantum dots in the presence of bromide and its sensing application
Sensors and Actuators B-chemical, 2016Co-Authors: Yongping Dong, Ying Zhou, Jiao Wang, Junjie ZhuAbstract:Abstract Electrogenerated chemiluminescence (ECL) of lucignein often suffered from weak signal at positive potential in neutral condition. In the present study, strong anodic ECL was obtained in neutral Lucigenin solution at a CdSe quantum dots modified glassy carbon electrode. Electrochemical results suggested that CdSe quantum dots can catalyze the oxidation of Lucigenin and bromide, which can generate the anodic ECL. The fluorescence and the ECL spectra revealed that ECL resonance energy transfer (ECL-RET) can occur between Lucigenin and CdSe quantum dots. The oxidation product of bromide can promote ECL-RET and increase the anodic ECL signal significantly. The mechanisms of the anodic ECL based on the ECL-RET were proposed. Cytochrome C exhibited apparent inhibiting effect on the anodic ECL emission, based on which a sensitive ECL sensor for the detection of cytochrome C was established.
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electrogenerated chemiluminescence of quantum dots with Lucigenin as coreactant for sensitive detection of catechol
Talanta, 2016Co-Authors: Yongping Dong, Ying Zhou, Jiao Wang, Yuqiong Dong, Chengming WangAbstract:Electrogenerated chemiluminescence (ECL) of quantum dots (QDs), including CdS, CdSe, CdTe, and CdSe@ZnS QDs, was comparatively studied in neutral Lucigenin solution without coreactants. Cathodic ECL signals were obtained at -1.2 V at different QDs modified gold electrodes (QDs/GEs) and the strongest ECL emission was obtained at the CdSe@ZnS QDs modified GE, which is nearly 7-times larger than other QDs modified GEs. The electrochemical results and the ECL spectrum revealed that the luminophor of the cathodic ECL is the excited state of QDs but not Lucigenin, revealing that Lucigenin can act as coreactant to generate cathodic ECL with QDs. Several impact factors, such as the amount of QDs, the supporting electrolytes, and the pH were investigated. Under the optimal condition, catechol exhibited apparent inhibiting effect on the cathodic ECL signal, based on which a new ECL sensor was developed and applied in the sensitive detection of catechol. The inhibited ECL intensity varied linearly with catechol concentration in the range of 5-1000 nM with a detection limit of 2 nM (S/N=3). The ECL sensor exhibited satisfied stability, repeatability, and selectivity. The mechanism of cathodic ECL was also proposed.
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electrogenerated chemiluminescence of Lucigenin in ethanol solution at a polycrystalline gold electrode
Electroanalysis, 2007Co-Authors: Hua Cui, Hao Zhang, Yongping Dong, Mingjuan Shi, Wei Wang, Jizhao GuoAbstract:The electrogenerated chemiluminescence (ECL) behavior of Lucigenin in ethanol solution at a polycrystalline gold electrode was studied under conventional cyclic voltammetric conditions. Compared with the ECL of Lucigenin in aqueous solution, one cathodic ECL peak (ECL-1 at −0.98 V versus SCE) with a shoulder (S1 at −0.42 V) and three new anodic ECL peaks (ECL-2 at −0.53 V, ECL-3 at 0.20 V, and ECL-4 at 0.51 V) were observed, respectively, on the curve of ECL intensity versus potential. The effects of initial potential scan direction, the presence of O2 or N2, potential scan ranges, supporting electrolyte and the concentration of Lucigenin on these ECL peaks were examined. The electrochemistry of Lucigenin in ethanol solution was also studied. The emitter of all ECL peaks was identified as N-methylacridone (NMA) by analyzing the ECL spectra. The mechanism for these ECL peaks is proposed to be due to the reactions of Lucigenin and its redox products such as Luc and DBA with dissolved oxygen or O2 electrogenerated by the dissolved oxygen at different potentials. The formation of new anodic ECL peaks in ethanol solution is due to longer lifetime of superoxide ions and easier electro-oxidation of DBA in nonaqueous solution, revealing that the solvent plays an important role in the Lucigenin ECL reactions.
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a new electrogenerated chemiluminescence peak of Lucigenin in the hydrogen evolution region induced by platinum nanoparticles
Journal of Physical Chemistry C, 2007Co-Authors: Jizhao Guo, Hua Cui, Yongping DongAbstract:The electrogenerated chemiluminescence (ECL) behavior of Lucigenin at a glassy carbon electrode in the presence of platinum nanoparticles dispersed in alkaline aqueous solutions was studied under conventional cyclic voltammetry (CV). Two ECL peaks were observed at −0.65 and −2.0 V (vs SCE), respectively. ECL-1 was a conventional ECL peak of Lucigenin also observed in the absence of platinum nanoparticles. ECL-2 was a new ECL peak appearing in the hydrogen-evolution potential region. It was found that ECL-1 decreased and ECL-2 increased with an increase in the concentration of platinum nanoparticles. The ECL properties under various conditions were studied. It has been proposed that ECL-2 is likely due to that reductive intermediate HadsPt0 formed during the hydrogen-evolution process that reduced Lucigenin cation (Luc2+) to monocation radial (Luc•+); Luc•+ and HadsPt0 reacted with dissolved oxygen to generate O2•-, which interacted with Luc•+ to produce the excited state N-methylacridone (NMA), giving ris...
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multichannel electrogenerated chemiluminescence of Lucigenin in neutral and alkaline aqueous solutions on a gold nanoparticle self assembled gold electrode
Journal of Electroanalytical Chemistry, 2006Co-Authors: Hua Cui, Yongping DongAbstract:Abstract The electrogenerated chemiluminescence (ECL) of Lucigenin on a gold nanoparticle self-assembled gold electrode in neutral and alkaline solutions was studied under conventional cyclic voltammetry (CV) conditions. The gold nanoparticle self-assembled gold electrode exhibited excellent ECL property for the Lucigenin ECL system. In alkaline solution, one sharp peak and a shoulder peak were observed at −0.24 and −0.36 V, respectively, on the curve of ECL intensity versus potential and the intensities of these peaks were enhanced by 2–3 orders of magnitude compared with those on a bare gold electrode. In neutral solution, two strong ECL peaks (ECL signal/noise = 100–1000) were also observed on a gold nanoparticle self-assembled gold electrode, whereas the two ECL peaks were undetectable on a bare gold electrode. These peaks were found to depend on gold nanoparticles on the surface of the electrode, potential scan direction and scan rate, the presence of O2 or N2, the pH, the concentration of Lucigenin and electrolyte, and surfactant. The emitter of all ECL peaks was identified as N-methylacridone (NMA). The mechanism for the formation of these ECL peaks has been proposed. The results indicate that strong ECL signals of Lucigenin system could be obtained on a gold nanoparticle self-assembled gold electrode both in alkaline and neutral solutions, which is even stronger than that of luminol system on a gold nanoparticle self-assembled gold electrode under the optimization conditions. Moreover, the gold nanoparticle self-assembled gold electrode also exhibits good stability for the Lucigenin ECL system, overcoming the problem of electrode fouling on a traditional electrode.
Muhammad Saqib - One of the best experts on this subject based on the ideXlab platform.
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Lucigenin-Tris(2-carboxyethyl)phosphine Chemiluminescence for Selective and Sensitive Detection of TCEP, Superoxide Dismutase, Mercury(II), and Dopamine
Analytical chemistry, 2019Co-Authors: Muhammad Saqib, Shahida Bashir, Shanshan Wang, Yongdong JinAbstract:Development of simple and effective chemiluminescence (CL) systems for multiple sensing applications is significantly important but still a challenge. Until now, the majority of CL systems primarily utilized hydrogen peroxide (H2O2) as coreactant, which is limited in its stability and selectivity due to the easy decomposition of H2O2 in the presence of several ions. In this study, we develop a new and intense CL system by combined use of tris(2-carboxyethyl)phosphine (TCEP), a highly solution stable and pH-tolerant tertiary phosphine, with Lucigenin for the first time. The effective pairing leads to a significant ∼23 times CL enhancement over classic the Lucigenin–H2O2 system without employing additional catalysts. By virtue of this fascinating platform, a sensitive CL method has been developed for the multiple detection of TCEP (LOD = 70 nM), Lucigenin (LOD = 4.0 nM), superoxide dismutase (LOD = 0.8 ng/mL), Hg2+(LOD = 0.3 nM), and dopamine (LOD = 3.0 nM), with a linear range of 0.1–320 μM, 0.01–55 μM, 0....
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Lucigenin-Tris(2-carboxyethyl)phosphine Chemiluminescence for Selective and Sensitive Detection of TCEP, Superoxide Dismutase, Mercury(II), and Dopamine
2019Co-Authors: Muhammad Saqib, Shahida Bashir, Shanshan Wang, Yongdong JinAbstract:Development of simple and effective chemiluminescence (CL) systems for multiple sensing applications is significantly important but still a challenge. Until now, the majority of CL systems primarily utilized hydrogen peroxide (H2O2) as coreactant, which is limited in its stability and selectivity due to the easy decomposition of H2O2 in the presence of several ions. In this study, we develop a new and intense CL system by combined use of tris(2-carboxyethyl)phosphine (TCEP), a highly solution stable and pH-tolerant tertiary phosphine, with Lucigenin for the first time. The effective pairing leads to a significant ∼23 times CL enhancement over classic the Lucigenin–H2O2 system without employing additional catalysts. By virtue of this fascinating platform, a sensitive CL method has been developed for the multiple detection of TCEP (LOD = 70 nM), Lucigenin (LOD = 4.0 nM), superoxide dismutase (LOD = 0.8 ng/mL), Hg2+(LOD = 0.3 nM), and dopamine (LOD = 3.0 nM), with a linear range of 0.1–320 μM, 0.01–55 μM, 0.005–0.5 μg/mL, 1.0–600 nM, and 0.01–0.8 μM, respectively. Remarkably, this CL method exhibited superior selectivity over several potential interferents. Moreover, the proposed method achieved excellent recoveries in the range of 94.0–102.3% for both Hg2+ detection in lake water and dopamine detection in human serum real samples. We envision that broad applications of TCEP may lead to construct new CL systems, pushing forward for efficient detection of various analytes
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pyridoxal 5 phosphate assay based on Lucigenin chemiluminescence
Mikrochimica Acta, 2018Co-Authors: Mohamed Ibrahim Halawa, Muhammad Saqib, Wenyue Gao, Wei ZhangAbstract:The authors describe the first chemiluminescence (CL) based method for determination of pyridoxal 5′-phosphate (PLP). PLP is found to generate intense CL with Lucigenin higher than that of the conventional Lucigenin-H2O2 system by a factor of about 9.0. This new finding is used to be in a detection method for PLP via flow injection analysis (FIA). Response is linear in the 50 nM to 200 μM PLP concentration range with a correlation coefficient of 0.998, and the detection limit (at an S/N of 3) is 6.9 nM. The assay is highly selective over various amino acids, vitamins, sugars, coenzymes and metal ions cofactors. It exhibits advantages over the commonly employed HPLC methods in that it is rapid, more economic, eco-friendly and high throughput FIA detection of PLP without the need for toxic derivatization reagents, organic solvents, and HPLC instrumentation. The method was successfully applied to the determination of PLP in (spiked) human blood samples with recoveries in the range from 96.2–101.6% with % RSD < 4.0. The new system is also employed to determine Lucigenin in the linear range of 0.3 to 100.0 μM with a correlation coefficient of 0.994 and the limit of detection is 0.04 μM.
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chemiluminescence of Lucigenin allantoin and its application for the detection of allantoin
Analytical Chemistry, 2017Co-Authors: Muhammad Saqib, Baohua Lou, Mohamed Ibrahim Halawa, Shimeles Addisu Kitte, Zhongyuan LiuAbstract:Allantoin has been reported as a promising biomarker for monitoring of oxidative stress in humans and widely utilized in a variety of topical pharmaceuticals and cosmetics. Currently, the detection of allantoin is achieved by using chromatographic coupled techniques, which needs sample pre-extraction, derivatization, complex matrixes, and expensive instrumentation. Herein we report both the intense chemiluminescence of allantoin with Lucigenin and the chemiluminescent detection of allantoin for the first time. The Lucigenin–allantoin system demonstrated chemiluminescence emission intensity 17 times higher than that of the classic Lucigenin–hydrogen peroxide system. Based on this fascinating phenomenon, a novel chemiluminescence method has been developed for the sensitive and selective allantoin determination with the combination of flow injection analysis. This method shows a linear calibration curve in the range 0.1–3000 μM with a detection limit (3σ/s) of 0.03 μM. Moreover, it was successfully utilized ...
