“Cosmetic electrochemistry”: the facile production of graphite microelectrode ensembles

Abstract

The facile and rapid production of microelectrode ensembles is shown to be possible using off-the-shelf cosmetic products and is exemplified with the electrochemical sensing of a toxic metal offering a novel fabrication methodology.

Development of polyaniline microarray electrodes for cadmium analysis

“…The surface of bare SPCE (Fig. 4A) is composed of flakes of graphite with various diameters, all in the micrometer range, which is in accordance with previously published results (Choudhry et al, 2010a;Gornall et al, 2009;Kadara et al, 2009a). From the comparison of bare and spray modified SPCE (data not shown), it can be concluded that the polymer present in the cosmetic spray filled in the gaps and reduced the amount of accessible graphite, which accounts for the reduction in the voltammetric peak current when the spray modification time was increased (Fig.…”

“…Cyclic voltammograms at 0.005 V s ( Fig. 1B) revealed the microelectrode behavior as presented in other studies (Choudhry et al, 2010a;Huang et al, 2009;Kadara et al, 2009b). Increasing the spray time had a significant reduction effect on the peak intensity and the peak-to-peak separation revealing that the cosmetic spray reduced the amount of accessible graphite ( Figs.…”

“…Microarrays are single microelectrodes wired in parallel, with each electrode diffusionally independent, yielding a signal by many orders of magnitude larger compared to individual microelectrodes (Krishnamoorthy et al, 2009;Orozco et al, 2010). These microelectrodes are in a fixed distance from their nearest neighbor; alternatively, random arrays of microelectrodes termed as ensembles due to no regular spacing between the neighboring microelectrodes can be applied (Choudhry et al, 2010a(Choudhry et al, , 2010bGornall et al, 2009). Electrochemical signal observed using the arrays corresponds to the total signal of all electrodes comprising the array.…”

“…Thus, a large analytical signal coupled with low background currents results in an increase of the analytical sensitivity allowing lower detection limits. Microelectrode arrays provide advantages such as high current densities, high temporal and spatial resolution, and reduced capacitive-charging currents; they also find use in environmental sensing particularly as analytical screening tools for heavy metals detection (Choudhry et al, 2010a;Honeychurch & Hart, 2003;Kadara et al, 2009b;Orozco et al, 2010;Domínguez-Renedo et al, 2007;Štulík et al, 2000). Since microarrays represent a large number of active discs, when the target analyte is in an analytically challenging medium such as an effluent containing surface passivating media, even though some microdiscs on the array become electrochemically inactive, the sensitivity is not severely affected due to the still high overall number of active discs.…”

“…European Community Regulation (European Commission, 2006) settles the maximum level for cadmium in muscle of some fish species as 0.1 mg kg −1 (wet mass). Cugnet et al (2009) and Khairy et al (2010) developed various modifications of screen-printed electrodes for the quantification of Cd 2+ while Choudhry et al (2010a) presented a facile production of graphite microelectrodes ensembles based on a cosmetic spray modification. In this study, the development of a new screenprinted carbon microelectrode mechanically modified with a cosmetic product and electropolymerized with aniline is reported.…”