Russian Journal of Electrochemistry - An excellent electrochemical sensor based on glassy carbon electrode (GCE) modified in order with polyvinyl pyrrolidone-dispersed reduced graphene oxide... 相似文献
We are presenting an electrochemical immunosensor for the determination of the β-agonist and food additive ractopamine. A glassy carbon electrode (GCE) was modified with gold nanoparticles and a film of a composite made from poly(arginine) and multi-walled carbon nanotubes. Antibody against ractopamine was immobilized on the surface of the modified GCE which then was blocked with bovine serum albumin. The assembly of the immunosensor was followed by electrochemical impedance spectroscopy. Results demonstrated that the semicircle diameter increases, indicating that the film formed on the surface hinders electron transfer due to formation of the antibody-antigen complex on the modified electrode. Under optimal conditions, the peak current obtained by differential pulse voltammetry decreases linearly with increasing ractopamine concentrations in the 0.1 nmol•L−1 to 1 μmol•L−1 concentration range. The lower detection limit is 0.1 nmol•L−1. The sensor displays good stability and reproducibility. The method was applied to the analysis of spiked swine feed samples and gave satisfactory results.
Talin protein was partially purified from human colorectal carcinoma tissues, which was subject to tryptic digestion. Immunoaffinity precipitation with specific antibodies that recognize diglycyl-lysine(Lys) remnants from tryptic digestion of ubiquitinated peptides was used to enrich ubiquitinated sites in talin. Mass spectrometry coupled with capillary reverse-phase high-performance liquid chromatography was used to analyze tlie enriched peptides. Specifically, four peptides containing diglycyl-Lys remnants from talin, namely, TAK(ub)VLVEDTK, QQQYK(ub) FLPSELRDEH, K(ub)STVLQQQYNR, and EGILK(ub)TAK can be determined using mass spectrometric data. This study provides an analytical method for further study in tlie relationship between ubiquitination modification of talin and its biological activity in colorectal cancer tissues with different pathological processes. 相似文献
An ultrasensitive paper based lateral flow assay is described for rapid and simultaneous fluorometric detection of several β-agonists including clenbuterol and its chemical analogues (mabuterol, brombuterol, cimaterol, cimbuterol, bromchlorbuterol and banbuterol). A nonspecific monoclonal antibody (mAb) against clenbuterol and its analogues was prepared and employed in a competitive immunoassay where mAb conjugated to fluorescent nanoparticles and free β-agonists compete for the binding sites. This enables rapid screening for the 7 β-agonists in a single run that takes about 8 min. Detection limits for the seven β-agonists are <50 pg g?1 of pork. Recoveries ranged from 69.5% to 102.4%, and relative standard deviations were ±15%. The assay was applied to the analysis of both using spiked and unspiked pork for β-agonists, and the results compare well to those obtained by HPLC-MS.