Voltammetric Determination of Glucose at Bismuth‐Modified Mesoporous Platinum Microelectrodes

Abstract

Mesoporous platinum microeletrodes (MPtEs) modified by a mono-or submonolayer of adsorbed bismuth (BiMPtE) 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 3þ 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 3þ 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.

Bismuth‐Coated Mesoporous Platinum Microelectrodes as Sensors for Formic Acid Detection

“…This electrode process leads to the release of the surface locations of the catalyst, and on the negative-going scan markedly larger anodic currents (wave 3) are observed, reflecting the HCOOH oxidation on the catalyst surface free from CO ads [18]. From Figure 2 it is also evident that the increase of the real surface area of the MPtEs provides a general increase of the current over the entire potential window investigated, as expected for electrode processes occurring under kinetic control [26][27][28]30]. As for peak 1, its current increases almost linearly with real surface area as is evident from data included in inset of Figure 2.…”

“…Platinum electrodes with high surface areas and welldefined periodic nanostructures have recently received increasing interest, because of their potential applications in electrocatalysis and electroanalysis [14,16,19,20,21,[25][26][27][28][29][30][31]. These electrode systems can be prepared by templating techniques from lyotropic liquid crystalline phases of non-ionic surfactants [32][33][34][35].…”

The Contribution of Microelectrodes to Electroanalytical Chemistry: From Reaction Mechanisms and Scanning Electrochemical Microscopy to Ocean Sensors

“…The approach described above has been applied to micro‐ and macroelectrodes to improve electroanalytical measurements, e. g., for the detection of high concentrations of H 2 O 2 ,76 the direct detection of glucose or electro oxidation of formic acid on Bi modified mesoporous microelectrodes,77, 78 the oxidation of H 2 O 2 at nanoporous platinum microelectrodes for the detection of glutamate,79 the improvement of anodic striping voltammetry,80 the detection of alcohol on mesoporous Ni electrodes,81 the detection of glucose on mesoporous Pt electrodes,82 or the simultaneous determination of catechol and hydroquinone at mesoporous platinum electrode 83…”

Differential Pulse Voltammetric Determination of 2‐Methyl‐4,6‐Dinitrophenol using Bismuth Bulk Electrode

“…Bismuth electrodes have been used for voltammetry since 2000 [10]. There are different types of bismuth electrodes, e. g. in situ and ex situ prepared bismuth-film electrodes (BiFEs) which can be preplated on carbon [11], glassy carbon [12], carbon fibres [13], carbon paste [14], graphite [15], gold [16], and platinum [17]. BiFEs have been used for the determination of various trace metals [10,[18][19][20][21][22] due to low toxicity, wide cathodic potential window, low noise, well defined and reproducible signals and simple and inexpensive preparation [10,14,23,24].…”