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Abstract: Direct and reversible electron transfer of myoglobin (Mb), for the first time, is achieved at nanopyramidal gold surface, which was fabricated by one-step electrodeposition, with redox formal potential of 0.21±0.01V (vs. Ag/AgCl) and an apparent heterogeneous electron-transfer rate constant (k s) of 1.6±0.2s−1. Electrochemical investigation indicates that Mb is stably confined on the nanopyramidal gold surface and maintains electrocatalytic activity toward hydrogen peroxide (H2O2). The facilitated electron transfer combined with the intrinsic catalytical activity of Mb substantially construct the third-generation biosensor for H2O2. The positive redox potential of Mb at the nanostructured gold electrode gives a strong basis for determination of H2O2 with high selectivity. Besides this advantage, the present biosensor also exhibits quick response time, broad linear range, and good sensitivity. The dynamic detection linear range is from 1μM to 1.4mM with a detection limit of 0.5μM at 3σ. The striking analytical performance of the present biosensor, as well as the biocompatibility of gold nanostructures provided a potential for continuous, on-line detection of H2O2 in the biological system. [Copyright &y& Elsevier]

This paper demonstrates a novel and facile technique for the production of microelectrode arrays based on either TiO2 or metal nanoparticles, which combines photolithography and photocatalytic deposition. A procedure that involves photolithographic selective decomposition of superhydrophobic n-octadecyltriethoxysilane (ODS) has been developed to create superhydrophobic/superhydrophilic TiO2 patterns (i.e., microelectrode arrays based on TiO2 nanoparticles). The generated TiO2 patterns can function as molecular microtemplates, in which elevated metal nanoparticle-based microelectrode arrays are produced by photocatalytic deposition to form microelectrode arrays based on metal nanoparticles. Microscopy and atomic force microscopy have demonstrated that the metal nanoparticles grow site-selectively inside the TiO2 microtemplates. This developed approach can be used to create microelectrode arrays composed by either TiO2 nanoparticles or various metal nanoparticles, such as gold, silver, and platinum, with different patterns. The electrochemical behavior of the as-prepared microelectrode arrays has also been characterized by cyclic voltammetry.