Screen-printed electrodes SPEs applications

For chemical monitoring, a list of priority substances has been established that includes metals such as cadmium, lead, and nickel. As far as metals are concerned, voltammetric techniques and more precisely electrochemical stripping analysis has long been recognized as a powerful technique in environmental samples. In particular, anodic stripping voltammetry (ASV) coupled with screen-printed electrodes (SPEs) is a great simplification in the design and operation of on site heavy metal determination in water, for reasons of cost, simplicity, speed, sensitivity, portability and simultaneous multi-analyte capabilities. The wide applications in the field for heavy metal detection were extensively reviewed (Honeychurch and Hart, 2003 Palchetti et al., 2005). 

The aim of this work is to demonstrate how the screen printed electrodes (SPEs) can be used for on site heavy metals monitoring in surface waters in the frame of the WFD. The sensors used consist of mercury-coated screen-printed electrodes coupled with square wave anodic stripping voltammetry (SWASV) (Palchetti et al., 1999). Three metals Cu, Cd, and Pb which are classically analysed in water matrices have been considered. Moreover, Cd and Pb belong to the priority substances list of the WFD. Performance criteria of the device are first established to evaluate the level of confidence of the method. The potential use of the device and its main advantages are then highlighted through two illustrative field applications. 

Screen-printed electrodes (SPEs) are devices that are produced by printing different inks on a suitable substrate. Through the application of this technique, it is possible to fabricate a chip containing working, reference, and auxiliary electrode or even multisensory array. Electrode fabrication requires an ink as a precursor, which is typically a mixture containing at least three compraients" (see also Chap. 16 of Volume I) ... 

As it has been mentioned in the previous section, due to the versatility of the production process of screen-printed electrodes, a wide range of SPEs can be made, containing only the working electrode, working and counter electrodes to work with an external reference electrode, a complete electrochemical cell, or even with multiple working electrodes, for applications where a disposable electrode is desired to perform electrochemical measurements Fig. 9.2. 

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