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71.
We presented a novel electrogenerated chemiluminescence (ECL) biosensor for monitoring the activity and inhibition of protein kinases based on signal amplification using enzyme-functionalized Au NPs nanoprobe. In this design, the biotin-DNA labeled glucose oxidase/Au NPs (GOx/Au NPs/DNA-biotin) nanoprobes, prepared by conjugating Au NPs with biotin-DNA and GOx, were bound to the biotinylated anti-phosphoserine labeled phosphorylated peptide modified electrode surface through a biotin−avidin interaction. The GOx assembled on the nanoprobe can catalyze glucose to generate H2O2 in the presence of O2 while the ECL reaction occurred in the luminol ECL biosensor. At a higher concentration of kinase, there are more nanoprobes on the electrode, which gives a higher amount of GOx at the electrode interface and thus higher electrocatalytic efficiency to the luminol ECL reaction. Therefore, the activity of protein kinases can be monitored by ECL with high sensitivity. Protein kinase A (PKA), an important enzyme in regulation of glycogen, sugar, and lipid metabolism in the human body, was used as a model to confirm the present proof-of-concept strategy. The as-proposed biosensor presents high sensitivity, low detection limit of 0.013 U mL−1, wide linear range (from 0.02 to 40 U mL−1), and excellent stability. Moreover, this biosensor can also be used for quantitative analysis of kinase inhibition. On the basis of the inhibitor concentration dependent ECL signal, the half-maximal inhibition value IC50 of ellagic acid, a typical PKA inhibitor, was estimated, which is in agreement with those obtained using the conventional kinase assay. The simple and sensitive biosensor is promising in developing a high-through assay of in vitro kinase activity and inhibitor screening for clinic diagnostic and drug development. 相似文献
72.
A novel molecule containing electron-rich carbazole and electron-deficient pyrimidine moieties exhibits useful and intriguing physical properties, including promising reversible redox behavior that gives rise to electrogenerated chemiluminescence (ECL). 相似文献
73.
A simple and sensitive liquid chromatographic method coupled with electrogenerated chemiluminescence (ECL) was described for the separation and quantification of naproxen in human urine. The method was based on the ECL of naproxen in basic NaNO3 solution with a dual-electrode system. Factors affected the ECL emission were investigated. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of naproxen in the range of 4.0 × 10−8 g mL−1 to 2.0 × 10−6 g mL−1 and the detection limit was 1.6 × 10−8 g mL−1 (S/N = 3). Application of the method to the analyses of naproxen in human urine proved feasible. 相似文献
74.
A simple electrochemical procedure for the N-acylation and N-alkylation of benzoxazol-2(3H)-ones has been set up via electrolysis of an ionic liquid containing a benzoxazolone followed by addition of saturated or unsaturated anhydrides or alkyl halides. The electrochemically induced N-functionalization of benzoxazol-2(3H)-ones works very well in all tested ionic liquids, avoiding the use of volatile organic solvents. The N-acyl and N-alkyl derivatives of benzoxazol-2(3H)-ones were isolated in good to excellent yields; moreover, the ionic liquid has been reused fivefold maintaining the high yield of the products. 相似文献
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76.
In this work, a stable electrogenerated chemiluminescence (ECL) detector was developed. The detector was prepared by packing cation-exchanged resin particles in a glass tube, followed by inserting Pt wires (working electrode) in this tube and sealing. The leakage of Ru(bpy)32+ can be compensated by adding a small amount of Ru(bpy)32+ into solution phase. Coupled with high-performance liquid chromatography separation, the detector has been used for determination of itopride hydrochloride in human serum. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of itopride hydrochloride in the range of 1.0 × 10−8 g mL−1 to 1.0 × 10−6 g mL−1 and the detection limit was 3 × 10−9 g mL−1 (S/N = 3). The as-prepared ECL detector displayed good sensitivity and stability. 相似文献
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78.
A novel, sensitive and versatile electrogenerated chemiluminescence biosensing platform is developed for monitoring activity and inhibition of protein kinase based on Ru(bpy)32+ functionalized gold nanoparticles (Ru(bpy)32+-AuNPs) mediated signal transduction. Ru(bpy)32+-AuNPs were formed by functionalizing AuNPs with Ru(bpy)32+ through electrostatic interactions and were used as thiol-versatile signal probe. Casein kinase II (CK2) and cAMP-dependent protein kinase (PKA), two classical protein kinase implicated in disease, were chosen as model protein kinases while a CK2-specific peptide (CRRRADDSDDDDD) and a PKA-specific peptide (CLRRASLG) were employed as molecular substrate for CK2 and PKA, respectively. The specific peptide was self-assembled onto the gold electrode via Au–S bond to form ECL biosensor. Upon thiophosphorylation of the peptide on the electrode in the presence of protein kinase and co-substrate adenosine-5’-(γ-thio)-triphosphate, Ru(bpy)32+-AuNPs was assembled onto the thiophosphorylated peptides via Au–S bond. The Ru(bpy)32+-AuNPs attached on electrode surface produce detectable ECL signal in the presence of coreactant tripropylamine. This strategy is promising for multiple protein kinase assay and kinase inhibitor profiling with high sensitivity, good selectivity and versatility. The ECL intensity is proportional to the activity of CK2 in the range of 0.01–0.5 unit/mL with a low detection limit of 0.008 unit/mL and to the activity of PKA in the range of 0.01–0.4 unit/mL with a detection limit of 0.005 unit/mL. Additionally, this assay was applied to the detection of CK2 in serum samples and the inhibition of CK2 and PKA. This work demonstrates that the developed ECL method can provide a sensitive and versatile platform for the detection of kinase activity and drug-screening. 相似文献
79.
An ultrasensitive electrogenerated chemiluminescence (ECL) detection method of DNA hybridization based on single-walled carbon-nanotubes (SWNT) carrying a large number of ruthenium complex tags was developed. The probe single strand DNA (ss-DNA) and ruthenium complex were loaded at SWNT, which was taken as an ECL probe. When the capture ss-DNA with a thiol group was self-assembled onto the surface of gold electrode, and then hybridized with target ss-DNA and further hybridized with the ECL probe to form DNA sandwich conjugate, a strong ECL response was electrochemically generated. The ECL intensity was linearly related to the concentration of perfect-matched target ss-DNA in the range from 2.4 × 10−14 to 1.7 × 10−12 M with a detection limit of 9.0 × l0−15 M. The ECL signal difference permitted to discriminate the perfect-matched target ss-DNA and two-base-mismatched ss-DNA. This work demonstrates that SWNT can provide an amplification platform for carrying a large number of ECL probe and thus resulting in an ultrasensitive ECL detection of DNA hybridization. 相似文献
80.
Gui-Fen Jie 《Talanta》2007,71(4):1476-1480
Electrogenerated chemiluminescence (ECL) of CdS nanotubes in aqueous solution and its sensing application were studied by entrapping the CdS nanotubes in carbon paste electrode. Two ECL peaks were observed at −0.9 V (ECL-1) and −1.2 V (ECL-2), respectively, when the potential was cycled between 0 and −1.6 V. The electrochemically reduced nanocrystal species of CdS nanotubes could collide with the oxidized species in an annihilation process to produce the peak of ECL-1. The electron-transfer reaction between the reduced CdS nanocrystal species and oxidant coreactants such as S2O82−, H2O2, and reduced dissolved oxygen led to the appearance of the ECL-2 peak. Based on the enhancing effect of H2O2 on ECL-2 intensity, a novel CdS ECL sensor was developed for H2O2 detection. The sensor exhibited a detection limit of 0.1 μM and a linear range from 0.5 μM to 0.01 mM. The relative standard deviations of five replicate determinations of 5 μM H2O2 was 2.6%. In addition, the ECL spectrum in aqueous solution also exhibited two peaks at 500 and 640 nm, respectively. 相似文献