Title :
Stripping voltammetric detection of trace heavy metals using gold ultramicroelectrode arrays
Author :
Gutierrez-Capitan, Manuel ; Baldi, Antoni ; Jimenez-Jorquera, Cecilia ; Fernandez-Sanchez, Cesar ; Gomez, Raquel ; Garcia, Virgile
Author_Institution :
CNM, Inst. de Microelectron. de Barcelona (IMB), UAB, Bellaterra, Spain
Abstract :
The sensitive and simultaneous detection of zinc (Zn), cadmium (Cd) and lead (Pb) at gold ultramicroelectrode arrays (UMEAs) is reported. The device performance was based on the square-wave anodic stripping voltammetric technique. This consisted of the co-deposition of a layer of bismuth (Bi) together with the heavy metal target analytes onto the UMEA surface by applying a constant negative potential of -1.3 V for 360 s, followed by the stripping of the heavy metal alloy deposited by an anodic potential scan in a suitable potential window. Peaks at potentials ca. -1.0, -0.75 and -0.5 V were recorded and could be ascribed to the Zn, Cd and Pb stripping processes, respectively. Measurements were carried out in standard 0.1 M acetate buffer solutions pH 4.5, containing increasing concentrations of the three analytes. By using the peak areas, the corresponding calibration curves were constructed. The results showed a good sensitivity with a linear range from 10 to 70 ppb and a limit of detection of 7.5 ppb Pb, 5.3 ppb Cd and 9.2 ppb Zn, respectively.
Keywords :
anodisation; cadmium; calibration; chemical sensors; gold; lead; microelectrodes; microsensors; voltammetry (chemical analysis); zinc; Au; Cd; Pb; Zn; acetate buffer solutions; anodic potential deposition; calibration curves; gold ultramicroelectrode arrays; square-wave anodic stripping voltammetric technique; time 360 s; trace heavy metals; voltage -1.3 V; Bismuth; Electrodes; Gold; Lead; Standards; Zinc; Bi film; gold ultramicroelectrode arrays; heavy metals; square wave anodic stripping voltammetry;
Conference_Titel :
Sensors (IBERSENSOR), 2014 IEEE 9th Ibero-American Congress on
Conference_Location :
Bogota
Print_ISBN :
978-1-4799-6835-0
DOI :
10.1109/IBERSENSOR.2014.6995557