the anode, required the large overpotential (η) to overcome the sluggish kinetically and hindered practical utilization of water splitting technology. [7][8][9] Efficient catalysts should be designed and synthesized to decrease the overpotential and accelerate the kinetically for the OER. Although state-of-the-art precious metalbased materials (e.g., RuO 2 or IrO 2 ) are the benchmark catalysts for OER, they are very costly due to their limited resources on earth. [10,11] Huge efforts have therefore been devoted to fabricate efficient and alternative electrocatalysts.Over the last few decades, extensive attentions have been paid to earth-abundant and cost-efficient (3d) transition metal-based alternatives. [1,7,9,12] Apart from the well-developed metal oxides and (oxy)hydroxides catalysts, [2,13]

An explosive situation: By using gold nanoparticles and taking advantage of the donor–acceptor interaction between trinitrotoluene (TNT) and cysteamine, the visualization of TNT can be achieved at picomolar levels (see picture). The color change from red to blue can be seen with the naked eye, which allows sensitive on‐the‐spot detection.

This study demonstrates a new electrochemical method for in vivo measurements of ascorbic acid (AA) in rat brain with multiwalled carbon nanotube (MWNT)-modified carbon fiber microelectrodes (CFMEs) based on the electrochemical property of MWNTs for facilitating AA oxidation. Cyclic voltammetry results indicate that the prepared MWNT-modified CFMEs possess a marked electrocatalytic activity toward AA oxidation and can be used for its selective measurement in the presence of other kinds of electroactive species coexisting in rat brain, such as 3,4-dihydroxyphenylacetic acid, uric acid, and 5-hydroxytryptamine. The selectivity of the MWNT-modified CFMEs toward AA measurement is further studied in vivo by exogenously infusing ascorbate oxidase into the brain, and the results confirm that the prepared electrodes are selective and can thus be used for reliable in vivo measurements of AA in rat brain, combined with their good stability during in vivo measurements. The basal level of striatum AA is determined to be 0.20 +/- 0.05 mM (n = 3). The application of the voltammetric method with the MWNT-modified CFMEs is preliminarily demonstrated for in vivo observation of homeostatic regulation of striatum AA with exogenous infusion of AA into the brain.