Silver based sensors from CD for chloride ions detection

This preliminary work shows a new and innovative way to produce silver based electrodes from compact discs and its application towards the detection of chloride ions. A complete sensor was obtained from the compact discs with working, reference and counter electrode made of silver. Chloride ions were detected by exploiting the high affinity of silver with this anion to produce silver chloride. This electrochemical oxidation of silver can be monitored by using an electrochemical technique such as linear scan voltammetry. Indeed, during linear scan voltammetry the oxidation of silver to silver chloride lead to a peak current that increases linearly with chloride concentration. Using this technique, a limit of detection <0.05 mM was found and the electrode shows high selectivity towards many chemicals. In order to very the possibility to recycle waste compact discs, the sensing platform was also obtained from burned compact discs and results shows a negligible interference from the burning process. The sensing platform has been used to quantify chloride ions in real samples showing high recovery rates.