ABSTRACT
Aggravated by human and industrial activities, heavy metal pollution has become a severe problem, causing widespread concern in society, and cannot be ignored. Herein, a graphene/gold nanoparticle-hybrid (AuNPs/ERGO) was proposed and synthesized by electrochemical methods. Based on the AuNPs/ERGO hybrid, a novel electrochemical sensing platform was established and successfully applied for the selective, quantitative detection of Hg2+, taking advantage of the well-established anodic stripping voltammetry (ASV). This hybrid material not only increases the surface area and charge transfer rate but also provides more active sites for Hg deposition due to the formation of homogeneous, high density and monodispersed AuNPs on the ERGO film. The prepared AuNPs/ERGO hybrid was modified on a glassy carbon electrode (GCE) to detect Hg2+ with a linear range from 0.5 to 20 µg L-1 and a low limit of detection (LOD) of 0.06 µg L-1. The selectivity and stability of the as-prepared electrode were investigated and showed promising results. In addition, a screen-printed carbon electrode (SPCE) was also employed to verify the practical application ability of our assay with an excellent performance, which presents a bright application prospect for in situ Hg2+ detection.
Subject(s)
Graphite , Mercury , Metal Nanoparticles , Carbon/chemistry , Electrodes , Gold/chemistry , Graphite/chemistry , Humans , Ions , Mercury/chemistry , Metal Nanoparticles/chemistryABSTRACT
Capillary electrophoresis has become a widely useful analytical technology. Amperometric detection is extensively employed in capillary electrophoresis for its many inherent virtues, such as rapid response, remarkable sensitivity, and low cost of both detectors and instrumentations. Analysis of inorganic and small organic ions by capillary electrophoresis is an important research field. This review focuses on the recent developments of capillary electrophoresis coupled with amperometric detection for analysis of inorganic and small organic ions. Advancements in electrophoresis separation modes, amperometric detection modes, working electrodes, and applications of inorganic ions, amino acids, phenols, and amines are discussed.
Subject(s)
Conductometry/instrumentation , Conductometry/methods , Electrophoresis, Capillary/instrumentation , Electrophoresis, Capillary/methods , Inorganic Chemicals/analysis , Ions , Amino Acids/analysis , Amino Acids/chemistry , Carbon/chemistry , Electrodes , Inorganic Chemicals/chemistry , Microchemistry , Nanostructures/chemistry , Phenols/analysis , Phenols/chemistry , Sensitivity and SpecificityABSTRACT
Images of Human umbilical vein endothelial cells (HUVECs) have been obtained and the regulation of cell morphology changes after nitric oxide release has been recorded and discerned quantitatively for the first time using scanning electrochemical microscopy.
Subject(s)
Endothelial Cells/metabolism , Endothelial Cells/ultrastructure , Microchemistry/methods , Nitric Oxide/metabolism , Carbon , Carbon Fiber , Electrochemistry , Humans , Microchemistry/instrumentation , Microelectrodes , Microscopy, Electron, ScanningABSTRACT
Carbon fiber nanoelectrodes (tip diameter = ca. 100 nm) have been first used to monitor real-time dopamine release from single living vesicles of single rat pheochromocytoma (PC12) cells. The experiments show that active and inactive release sites exist on the surface of cells, and the spatial distributions have been differentiated even in the same active release zone. It is first demonstrated that multiple vesicles can sequentially release dopamine at the same site of the cell surface, which possibly plays the main role in the dopamine release from PC12 cells.
