Regulating the work function and surface hydrophobicity of an indium tin oxide electrode for enhanced electrochemiluminescence analysis.

The electrochemical properties of the indium tin oxide (ITO) electrode were improved significantly by surface modification with ethephon and an ultrathin polydimethylsiloxane (PDMS) layer to regulate the work function and surface hydrophobicity of ITO. Based on this strategy, the electrochemiluminescence (ECL) intensity of tris(2,2'-bipyridyl)ruthenium (Ru(bpy)) and tri--propylamine (TPrA) in solution and on a microbead surface can be enhanced by 110 and 2 times, respectively. When using the modified electrode to detect nicotinamide adenine dinucleotide (NADH), the linear range (5-1000 μM) was increased dramatically in comparison with a bare ITO electrode, with a limit of detection of 1.

Dual-Coreactants Enhanced Electrochemiluminescence.

The electrochemiluminescence (ECL) of ruthenium(II) tris(2,2'-bipyridyl) (Ru(bpy) ) with tri-n-propylamine (TPrA) as the good coreactant can be unexpectedly enhanced by a weak coreactant, such as triethanolamine (TEOA). First, the intensity of ECL emitted by Ru(bpy) /TPrA can be remarkably amplified by 10.8-fold after adding some amount of TEOA.

Electrochemiluminescence Enhanced by a Non-Emissive Dual Redox Mediator.

A sulfonated tris(1-phenylpyrazolato)iridium(III) complex ([Ir(sppz)]) serves as a proof-of-concept non-emissive enhancer of the widely used ECL detection system of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)]) with tri-n-propylamine (TPrA) co-reactant, acting through electrocatalysis of TPrA oxidation and efficient chemi-excitation of the luminophore. Using self-interference ECL spectroscopy, we show that the enhancer extends diffusion of the required electrogenerated precursors from the electrode surface. Previously reported enhancement through these pathways has been confounded by the inherent ECL of the enhancer, but the increase in [Ru(bpy)] ECL intensity using [Ir(sppz)] was obtained without its concomitant emission.

Recent Advances in Electrochemiluminescence Visual Biosensing and Bioimaging.

Electrochemiluminescence (ECL) is one of the most powerful techniques that meet the needs of analysis and detection in a variety of scenarios, because of its highly analytical sensitivity and excellent spatiotemporal controllability. ECL combined with microscopy (ECLM) offers a promising approach for quantifying and mapping a wide range of analytes. To date, ECLM has been widely used to image biological entities and processes, such as cells, subcellular structures, proteins and membrane transport properties.

Electrochemiluminescence Distance and Reactivity of Coreactants Determine the Sensitivity of Bead-Based Immunoassays.

Herein we report the study of electrochemiluminescence (ECL) generation by tris(2,2'-bipyridyl)ruthenium (Ru(bpy) ) and five tertiary amine coreactants. The ECL distance and lifetime of coreactant radical cations were measured by ECL self-interference spectroscopy. And the reactivity of coreactants was quantitatively evaluated in terms of integrated ECL intensity.

Confined Electrochemiluminescence Generation at Ultra-High-Density Gold Microwell Electrodes.

Electrochemiluminescence (ECL) imaging analysis based on the ultra-high-density microwell electrode array (UMEA) has been successfully used in biosensing and diagnostics, while the studies of ECL generation mechanisms with spatial resolution remain scarce. Herein we fabricate a gold-coated polydimethylsiloxane (PDMS) UMEA using electroless deposition method for the visualization of ECL reaction process at the single microwell level in conjunction with using microscopic ECL imaging technique, demonstrating that the microwell gold walls are indeed capable of enhancing the ECL generation. For the classical ECL system involving tris(2,2'-bipyridyl)ruthenium (Ru(bpy) ) and tri--propylamine (TPrA), the ECL image of a single microwell appears as a surface-confined ring, indicating the ECL intensity generated inside the well is much stronger than that on the top surface of UMEA.

Nanochannel Templated Iridium Oxide Nanostructures for Wide-Range pH Sensing from Solutions to Human Skin Surface.

Herein we report the fabrication of highly sensitive solid-state pH sensors based on iridium oxide nanowires (IONWs) for a wide-range of pH measurements. IONWs were confined electrodeposits on the indium tin oxide (ITO) electrode using a highly ordered silica nanochannel membrane as the template. Subsequently removing the template produced amorphous IONWs consisting of hydrated iridium oxyhydroxides.

Electrodeposition of nickel nanostructures using silica nanochannels as confinement for low-fouling enzyme-free glucose detection.

This work reports an enzyme-free glucose sensor based on nickel nanostructures electrodeposited on a fluorine-doped tin oxide (FTO) electrode modified with a silica nanochannel membrane (SNM). The SNM consists of a high density of nanochannels vertically oriented to the electrode surface, which can spatially confine the electrodeposition of nickel nanostructures and protect them to make Ni@SNM/FTO electrodes. In alkaline media, nickel could be converted to nickel oxyhydroxide that displayed catalytic activity toward the anodic oxidation of glucose.