Graphene nanoplatelets (GNPs) are 'tagged' with 1-(biphen-4-yl)ferrocene. Chronoamperometry is then utilised to observe single particle impacts when GNPs suspended in solution collide with a carbon fibre micro wire electrode held at an oxidising potential, resulting in current/time transient "spikes". The impacts are associated with two types of charge transfer: Faradaic due to oxidation of the...

The effect of the electrolyte concentration (NaCl aqueous electrolyte) on the dimensional variations of films of polypyrrole doped with dodecylbenzenesulfonate PPy(DBS) on Pt and Au wires was studied. Any parallel reaction that occurs during the redox polymeric reaction that drives the mechanical actuation, as detected from the coulovoltammetric responses, was avoided by using Pt wires as subst...

The in vitro and in vivo electrochemical detection of the reduced form of glutathione (L-γ-glutamyl-L-cysteinyl-glycine, GSH) using boron doped diamond (BDD) microelectrode for potential application in the assessment of cancerous tumors is presented. Accurate calibration curve for the determination of GSH could be obtained by the in vitro electrochemical measurements. Additionally, it was shown...

The influence of polyethyleneimine (PEI) on the electrochemical behavior of cyanide-free electrolytes with 5,5-dimethylhydantoin (DMH) as a complexing agent was investigated using cyclic voltammetry (CV), chronoamperometry, and cathodic polarization measurements. The gold electrodeposition displayed three-dimensional (3-D) progressive nucleation in both the absence and presence of PEI according...

Direct Electron Transfer biosensors, facilitating direct communication between the biomolecule of interest and electrode surface, are preferable compared to enzymatic and mediator based sensors. Although hemoglobin (Hb) contains four redox active iron centres, direct detection is not possible due to inaccessibility of iron centres and formation of dimers, blocking electron transfer. Through the...

The present work demonstrates that simultaneous determination of ascorbic acid (AA), uric acid (UA) and acetaminophen (ACT) can be performed on a novel single walled carbon nanotubes (SWCNTs), chitosan (CHIT) and MCM-41 composite modified glassy carbon electrode (SWCNTs-CHIT-MCM-41/GCE). The electro-oxidations of AA, UA and ACT were investigated by using differential pulse voltammetry (DPV), ch...

We aim to develop an in situ microfluidic biosensor based on laccase from Trametes pubescens with flow-injection and amperometry as the transducer method. The enzyme was directly immobilized by potential step chronoamperometry, and the immobilization was studied using cyclic voltammetry and electrochemical impedance spectroscopy. The electrode response by amperometry was probed using ABTS and s...

Nanostructured network-like MnO2-NiO composite electrodes were electrodeposited onto stainless steel substrates via different electrodeposition modes, such as chronopotentiometry, chronoamperometry, and cyclic voltammetry, and then subjected to heat treatment at 300°C for metal oxide conversion. X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy...

The electrochemical behaviour of ferrocene (Fc) is investigated in six different deep eutectic solvents (DESs) formed by means of hydrogen bonding between selected ammonium and phosphonium salts with glycerol and ethylene glycol. Combinations of cyclic voltammetry and chronoamperometry are employed to characterise the DESs. The reductive and oxidative potential limits are reported versus the Fc...

We propose chlorpromazine (CHP) as a new mediator for the rapid, sensitive, and highly selective voltammetric determination of homocysteine (Hcy) using multiwall carbon nanotube paste electrode (MWCNTPE). The experimental results showed that the carbon nanotube paste electrode has a highly electrocatalytic activity for the oxidation of Hcy in the presence of CHP as a mediator. Cyclic voltammetr...