Ordered Macroporous Ruthenium Oxide Electrodes for Potentiometric and Amperometric Sensing Applications

Abstract

We report two methods to prepare ordered macroporous ruthenium oxide electrodes based on a template approach and their possible applications as potentiometric and amperometric sensors. The very stable porous electrodes have been prepared using two techniques to assemble the colloidal template: the controlled evaporation (CE) technique and the Langmuir-Blodgett (LB) technique, followed by electrochemical deposition of ruthenium oxide. The increased surface area of the macroporous structure makes them attractive for electroanalytical applications such as potentiometric and amperometric sensors as is illustrated for pH sensing and direct oxidation of NADH, which is an important ingredient in dehydrogenase based biosensors.

Voltammetry at porous electrodes: A theoretical study

“…Table 1 shows recent examples of the use of porous electrodes fabricated in this manner in electrochemical sensing, where both improved sensitivity and limits of detection are often claimed. These include the detection of species such as NADH, [1][2][3] glucose, 4-6 nitrobenzene 7 and hydrogen peroxide, 8 in addition to a number of immunosensors.…”

A nanoporous ruthenium oxide framework for amperometric sensing of glucose and potentiometric sensing of pH

“…6.5±2.0 s). The pH response of L 2 -eRuO on Au wire electrode (0.5 mm in diameter) also revealed a slope of −55.2 mV pH −1 , which showed the possibility of miniaturization for local pH sensing [24]. Note that the reported value for L 2 -ePt showed a slope of −51 mV pH −1 and response time of t 95% 0ca.…”

“…Ruthenium oxide has received attention for catalytic applications [21,22] and pH measurements [23] due to its metallic conductivity and thermal stability. As far as we know, no porous RuO 2 electrode has been reported except macroporous Ru oxide electrode for pH and NADH sensing via templates by the controlled evaporation (CE) and Langmuir-Blodgett (LB) technique [24]. In this study, we have applied simple fabrication method for 3D-nanoporous Ru oxide film, L 2 -eRuO, using a reverse micelle surfactant procedure, where several day evaporation time in CE technique or the LB trough in LB technique are not necessary.…”

Electrocatalysis Using Porous Nanostructured Materials

“…In the hydro- www.chemphyschem.org thermal-assisted seed growth method, [52] platinum particles are first deposited electrochemically on titanium substrates without structure-directing agents. Moreover, ruthenium oxide [58] was synthesized in a similar way; however, in this case, the structure-directing agent was polystyrene. [53] Nanostructured (mesoporous) electrodes of metals such as Pt [54,55] and Au [56,57] can also be synthesized by electrochemical deposition through electroreduction of a metal salt in the presence of hard or soft templates, such as silica colloids, [56,57] polystyrene (PS) particles, [57] or micelles of octaethylene glycol monohexadecyl ether (C 16 EO 8 ) [54,55] (see Section 2.1).…”

“…[53] Nanostructured (mesoporous) electrodes of metals such as Pt [54,55] and Au [56,57] can also be synthesized by electrochemical deposition through electroreduction of a metal salt in the presence of hard or soft templates, such as silica colloids, [56,57] polystyrene (PS) particles, [57] or micelles of octaethylene glycol monohexadecyl ether (C 16 EO 8 ) [54,55] (see Section 2.1). Moreover, ruthenium oxide [58] was synthesized in a similar way; however, in this case, the structure-directing agent was polystyrene. Methanol oxidation on porous platinum catalysts was studied by Garcia et al [55] In many syntheses it is necessary to use a templating method before the electrochemical deposition of the electrocatalytic active material can be carried out.…”