Herein we report the study of electrochemiluminescence (ECL) generation by tris(2,2'bipyridyl)ruthenium (Ru(bpy) 3 2 + ) and five tertiary amine coreactants. The ECL distance and lifetime of coreactant radical cations were measured by ECL selfinterference spectroscopy. And the reactivity of coreactants was quantitatively evaluated in terms of integrated ECL intensity. By statistical analysis of ECL images of single Ru(bpy) 3 2 + -labeled microbeads, we propose that ECL distance and reactivity of coreactant codetermine the emission intensity and thus the sensitivity of immunoassay. 2,2-bis(hydroxymethyl)-2,2',2''-nitrilotriethanol (BIS-TRIS) can well balance ECL distancereactivity trade-off and enhance the sensitivity by 236 % compared with tri-n-propylamine (TPrA) in the beadbased immunoassay of carcinoembryonic antigen. The study brings an insightful understanding of ECL generation in bead-based immunoassay and a way of maximizing the analytical sensitivity from the aspect of coreactant.

Hydrogen peroxide (H 2 O 2 ) is an important molecule that is widely used or exists in foods, medicines, detergents and human body. Therefore, fast and accurate detection of H 2 O 2 is highly important in food security, disease diagnosis, etc. In this work, we report the fabrication of platinized silica nanoporous membrane (Pt@SNM) electrodes for the detection of H 2 O 2 in complex in vitro and in vivo environments. The porous structure of SNM can effectively confine the electrodeposition of Pt nanostructures and meanwhile prevent the adsorption of fouling species on the underlying electrode. In comparison with conventional electrodes for H 2 O 2 detection, the current one exhibited excellent antifouling ability and worked well in complex real samples. As we demonstrated that the Pt@SNM modified carbon fiber microelectrode could work pretty stably in cortex of rat brain up to 90 min. We believe that this methodology can be extended for electrochemical detection of many other species in strongly fouling media.[a] X.

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).

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. The IONW/ITO sensor can rapidly respond to the pH of the aqueous solutions in a wide range (from 0 to 13), avoiding the acid and alkaline errors encountered by conventional pH electrodes and exhibiting a super-Nernst analytical sensitivity as high as 235.5 mV/pH in the very acidic range of ∼0–2.5 and 90.1 mV/pH beyond (pH = ∼2.5–13). The sensitivity was associated with the interconversion of oxidation states of iridium oxyhydroxides. While in the very acidic range, intercalation of Cl– was proved to be responsible for the exceptionally high pH sensitivity. Moreover, the sensor was also demonstrated to work in organic solutions too. Finally, the flexible IONW/ITO electrode was prepared and interfaced to a wireless electrochemical device for real-time epidermal pH analysis with smartphones.