Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Micro-optical ring electrode
T2 - Development of a novel electrode for photoelectrochemistry
AU - Pennarun, G I
AU - Boxall, C
AU - OHare, D
PY - 1996/12
Y1 - 1996/12
N2 - The design of a novel photoelectrochemical sensor, the micro-optical ring electrode (MORE), is described, Based on a thin-ring microelectrode and using a fibre-optic light guide as the insulating material interior to the ring, the MORE is capable of delivering light directly to the region of electrochemical measurement and can therefore be used to conduct microelectrochemical studies of systems with complex photochemistry. A novel fabrication procedure is described, involving the coating of commercially available fibre optics (radius 1.25 x 10(-4) m) with a 600 nm layer of gold, so allowing exploitation of the electroanalytical advantages peculiar to thin-ring microelectrodes. The dark electrochemistry of the thin-ring microelectrode is characterized by use of cyclic voltammetry and chronoamperometry and found to agree with previously published theoretical results, Preliminary exploration of the photoelectrochemical response of the MORE is reported, achieved via the interrogation of the photoelectrochemically active phenothiazine dye methylene blue (MB(+)), Photocurrent signals obtained during cyclic voltammetric and chronoamperometric: studies of MB(+), conducted with the MORE under illuminated conditions and in the absence of any deliberately added reducing agent, are attributed to the formation and subsequent detection of (3)MB(+) within the diffusion layer of the microring electrode, The data demonstrate that the use of the MORE for the direct electrochemical detection of photogenerated species with lifetimes of <9 x 10(-5) s is possible, The electrochemistry of (3)MB(+) over the applied potential range from -0.4 to +1.0 V versus SCE is elucidated and discussed in the context of the behaviour of photoexcited MB(+) in the presence of the deliberately added reducing agent Fe2+.
AB - The design of a novel photoelectrochemical sensor, the micro-optical ring electrode (MORE), is described, Based on a thin-ring microelectrode and using a fibre-optic light guide as the insulating material interior to the ring, the MORE is capable of delivering light directly to the region of electrochemical measurement and can therefore be used to conduct microelectrochemical studies of systems with complex photochemistry. A novel fabrication procedure is described, involving the coating of commercially available fibre optics (radius 1.25 x 10(-4) m) with a 600 nm layer of gold, so allowing exploitation of the electroanalytical advantages peculiar to thin-ring microelectrodes. The dark electrochemistry of the thin-ring microelectrode is characterized by use of cyclic voltammetry and chronoamperometry and found to agree with previously published theoretical results, Preliminary exploration of the photoelectrochemical response of the MORE is reported, achieved via the interrogation of the photoelectrochemically active phenothiazine dye methylene blue (MB(+)), Photocurrent signals obtained during cyclic voltammetric and chronoamperometric: studies of MB(+), conducted with the MORE under illuminated conditions and in the absence of any deliberately added reducing agent, are attributed to the formation and subsequent detection of (3)MB(+) within the diffusion layer of the microring electrode, The data demonstrate that the use of the MORE for the direct electrochemical detection of photogenerated species with lifetimes of <9 x 10(-5) s is possible, The electrochemistry of (3)MB(+) over the applied potential range from -0.4 to +1.0 V versus SCE is elucidated and discussed in the context of the behaviour of photoexcited MB(+) in the presence of the deliberately added reducing agent Fe2+.
KW - ring microelectrode
KW - photoelectrochemistry
KW - optical electrode
KW - fibre optic
KW - methylene blue
KW - MODIFIED GOLD ELECTRODE
KW - BLUE REDOX COUPLE
KW - METHYLENE-BLUE
KW - SUPRAMOLECULAR PHENOMENA
KW - PHOTOGALVANIC CELLS
KW - NAFION FILMS
KW - TIO2 FILMS
KW - VOLTAMMETRY
KW - SYSTEMS
KW - MICROELECTRODES
U2 - 10.1039/AN9962101779
DO - 10.1039/AN9962101779
M3 - Journal article
VL - 121
SP - 1779
EP - 1788
JO - Analyst
JF - Analyst
SN - 0003-2654
IS - 12
ER -