Dongping Zhan

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The electrochemistry of dopamine (DA) was studied by cyclic voltammetry at a glassy carbon electrode modified by a gel containing multi-walled carbon nanotubes (MWNTs) and room-temperature ionic liquid of 1-octyl-3-methylimidazolium hexafluorophosphate (OMIMPF(6)). The thickness of gel on the surface of the electrode has to be controlled carefully because(More)
We report the use of a micropipet-supported ITIES (interface between two immiscible electrolyte solutions, also called a liquid/liquid (L/L) or water/oil (W/O) interface) as a scanning electrochemical microscopy (SECM) tip to detect silver ion and explore Ag+ toxicity in living cells. A 1,2-dichloroethane solution containing a commercially available(More)
Nanoelectrochemical approaches were used to investigate adsorption/desorption of hydrogen on Pt electrodes. These processes, which have been extensively studied over the last century, remain of current interest because of their applications in energy storage systems. The effective surface area of a nanoelectrode was found to be much larger than its(More)
Dopamine is an important neurotransmitter in mammalian central and peripheral nervous systems and is also a medicament to cure some neuropsychosis. In this work, ion transfer (IT), facilitated ion transfer (FIT) of protonated dopamine, and electron transfer (ET) between dopamine and ferrocene are investigated at the water/1,2-dichloroethane (W/DCE)(More)
We report that silver ion (Ag(+)) uptake is enhanced by 4-aminopyridine (4-AP), a well known voltage-sensitive potassium ion channel (K(v)) blocker. Both bacterial (Escherichia coli) and mammalian (3T3 fibroblast) cells were used as model systems. Ag(+) uptake was monitored with a scanning electrochemical microscope with an amperometric Ag(+) ion-selective(More)
Improving electrochemical activity of graphene is crucial for its various applications, which requires delicate control over its geometric and electronic structures. We demonstrate that precise control of the density of vacancy defects, introduced by Ar(+) irradiation, can improve and finely tune the heterogeneous electron transfer (HET) rate of graphene.(More)
Demonstrated in this article is that a palladium metal film can be applied to decouple the electric circuitry of electrochemical detection from that of the electrophoretic separation in an electrophoresis chip. The Pd solid-state field decoupler, as well as the working electrodes, is thermally evaporated onto the plastic chip and oriented vertically across(More)
Substrate leveling is an essential but neglected instrumental technique of scanning electrochemical microscopy (SECM). In this technical note, we provide an effective substrate leveling method based on the current feedback mode of SECM. By using an air-bearing rotary stage as the supporter of an electrolytic cell, the current feedback presents a periodic(More)
Large-area nanostructured Ag/Ag-tetracyanoquinodimethane (TCNQ) Schottky junctions are fabricated electrochemically on a mesoporous polyethylene terephthalate (PET) membrane-supported water/1, 2-dichloroethane (DCE) interface. When the interface is polarized, Ag(+) ions transfer across the PET membrane from the aqueous phase and are reduced to form metallic(More)
In this Article we have used new approaches to investigate a well-known chemical process, the propagation of electrochemical signals through a thin glass membrane. This process, which has been extensively studied over the last century, is the basis of the response of a potentiometric glass pH sensor; however, no amperometric glass sensors have yet been(More)