title: Screen-printed back-to-back electroanalytical sensors: heavy metal ion sensing.
abstract: Screen-printed back-to-back microband electroanalytical sensors are applied to the quantification of lead(II) ions for the first time. In this configuration the electrodes are positioned back-to-back with a common electrical connection to the two working electrodes with the counter and reference electrodes for each connected in the same manner as a normal "traditional" screen-printed sensor. Proof-of-concept is demonstrated for the electroanalytical sensing of lead(II) ions utilising square-wave anodic stripping voltammetry where an increase in the electroanalytical sensitivity is observed by a factor of 5 with the back-to-back microband configuration at a fixed lead(II) ion concentration of 5 μg L(-1) utilising a deposition potential and time of -1.2 V and 30 seconds respectively, compared to a conventional (single) microband electrode. The back-to-back microband configuration allows for the sensing of lead(II) ions with a linear range from 5 to 110 μg L(-1) with a limit of detection (based on 3σ) corresponding to 3.7 μg L(-1). The back-to-back microband configuration is demonstrated to quantify the levels of lead(II) ions within drinking water corresponding to a level of 2.8 (±0.3) μg L(-1). Independent validation was performed using ICP-OES with the levels of lead(II) ions found to correspond to 2.5 (±0.1) μg L(-1); the excellent agreement between the two methods validates the electroanalytical procedure for the quantification of lead(II) ions in drinking water. This back-to-back configuration exhibits an excellent validated analytical performance for the determination of lead(II) ions within drinking water at World Health Organisation levels (limited to 10 μg L(-1) within drinking water).
authors.affiliation: Faculty of Science and Engineering, School of Chemistry and the Environment, Division of Chemistry and Environmental Science, Manchester Metropolitan University, Chester Street, Manchester M15 GD, UK.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Ruas de Souza
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Foster
authors.forename: Athanasios V
authors.initials: AV
authors.lastname: Kolliopoulos
authors.forename: Mauro
authors.initials: M
authors.lastname: Bertotti
authors.forename: Craig E
authors.initials: CE
authors.lastname: Banks