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Voltammetric Determination of Glucose at Bismuth‐Modified Mesoporous Platinum Microelectrodes
Author(s) -
Daniele Salvatore,
Battistel Dario,
Bergamin Simone,
Bragato Carlo
Publication year - 2010
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200970014
Subject(s) - platinum , mesoporous material , bismuth , inorganic chemistry , cyclic voltammetry , adsorption , ascorbic acid , chemistry , underpotential deposition , aqueous solution , desorption , electrode , analytical chemistry (journal) , materials science , electrochemistry , catalysis , chromatography , organic chemistry , food science
Mesoporous platinum microeletrodes (MPtEs) modified by a mono‐ or submonolayer of adsorbed bismuth (Bi‐MPtE) were investigated and employed for the detection of glucose in 0.2 M NaOH solutions. The mesoporous platinum films were electrodeposited from hexachloroplatinic acid dissolved in the aqueous domain of the lyotropic liquid crystalline phase of octaethylene glycol monohexadecyl ether. Bismuth ad‐atoms were obtained by under potential deposition of Bi 3+ ions in 0.5 M H 2 SO 4 solutions. The coverage of the MPtEs by irreversibly adsorbed bismuth was checked in either a 0.5 M H 2 SO 4 or 0.2 M NaOH solution free of Bi 3+ ions, and exploiting the charge involved in the hydrogen adsorption/desorption peaks, which decreased in proportion to the amount of platinum sites covered by bismuth. The catalytic activity of a series of Bi‐MPtEs towards the oxidation of glucose was investigated by cyclic voltammetry, and the overall behaviour was found to be superior of that of the corresponding MPtEs. Also, at Bi‐MPtEs, the effect of interference by ascorbic acid was minimal. Calibration plots were examined over the glucose concentration range from 0.5 mM to 300 mM. It was found that linearity, between current against glucose concentration, and sensitivity depended on the electrode type and real surface area. At the Bi‐MPtEs both linear range and sensitivity were larger than those of the MPtEs. These results were discussed in terms of high tolerance of the Bi‐MPtEs towards the intermediate poisons originated in the electrooxidation process of glucose.