Yanan Yu

Nickel nanoparticle-modified electrode for ultra-sensitive electrochemical detection of insulin.

An ultra-sensitive electrochemical sensor for the detection of insulin was fabricated, using low-cost and environmentally friendly nickel nanoparticles (NiNPs) by ion implantation. The morphology and structure of the NiNPs are characterized by scanning electron microscopy (SEM), revealing diameters ranging from 4 to 8 nm. The insulin assay performances were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (I-t). The NiNPs-modified indium tin oxide electrode (NiNPs/ITO) showed excellent analytical features, including ultra-high sensitivity (2140 μAμM(-1)) for detecting low concentrations of insulin, an incredibly low detection limit (10 pM) and a wide dynamic range (100 pM to 2400 pM and 1 nM to 125 nM). In addition, the NiNPs/ITO electrode was also used to analyze the insulin concentration in bovine insulin injections. The NiNPs/ITO electrode is expected to be used as a potential biosensor for insulin.

A bimetallic Ni–Ti nanoparticle modified indium tin oxide electrode fabricated by the ion implantation method for studying the direct electrocatalytic oxidation of methanol

This study has investigated the oxidation of methanol (CH3OH) on a novel bimetallic Ni–Ti nanoparticle-modified indium tin oxide electrode (Ni–Ti NP/ITO) fabricated by the ion implantation method. This has been shown to be a facile, effective and eco-friendly method that could potentially be used to manufacture modified electrodes. The modified electrode exhibits a high electrochemical activity. The techniques of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) techniques were used to characterize an ITO electrode modified by Ti nanoparticles (Ti NP/ITO), an ITO electrode modified by Ni nanoparticles (Ni NP/ITO) and the morphology and performance of Ni–Ti NP/ITO. The size of the bimetallic Ni–Ti nanoparticles (Ni–Ti NPs) is in the range of 20–30 nm based on SEM analysis. The Ni nanoparticles (Ni NPs) and Ti nanoparticles (Ti NPs) formed on the electrode are in the Ni0 and Ti(IV) metallic states as determined by XPS. The general electrochemical behaviours of the modified electrode were characterized by CV. The Ni–Ti NP/ITO electrode exhibited good electrocatalytic activity for the oxidation of methanol with long-term stability and has possible applications in fuel cells.

A cobalt nanoparticle ion-implantation-modified indium tin oxide electrode for direct electrocatalytic oxidation of methanol in alkaline media

In this work, cobalt-nanoparticles (CoNPs) were prepared on an indium tin oxide (ITO) electrode by ion implantation, which is a novel, low-cost and environmentally friendly process. Then, the CoNP/ITO electrode was annealed at 300 °C for 2 h in a Muffle furnace, forming the annealed-CoNP/ITO electrode. The morphology and composition of the CoNPs and annealed-CoNPs were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Their electrocatalytic performance was also studied by electrochemical impedance spectra (EIS) and cyclic voltammetry (CV) under optimized conditions. Compared with the annealed-CoNP/ITO electrode, the result indicates that the CoNP/ITO electrode enhances the electrocatalytic activity and stability for direct methanol oxidation in alkaline media and can be used in fuel cells.