A sensor based on a screen-printed electrode (SPE) modified with a stable dispersion of commercially available carbon black (CB) N220 was optimised and challenged with several thiol-containing compounds. This probe showed a significantly enhanced electrochemical activity respect to a bare SPE when tested with thiocholine, cysteine, glutathione and cysteamine. When challenged in amperometric batch mode, the response was stable and showed a linear dependence up to 1 × 10-5 mol l-1 for thiocholine and cysteine. The very high sensitivity towards these thiols (299 mA mol -1 l cm-2 for thiocholine and 441 mA mol-1 l cm-2 for cysteine) was then used as the basis for developing an analytical method for mercury ion detection since a non electroactive complex (thiol-Hg) is formed in the presence of the metal. By selecting an appropriate concentration of thiocholine, a concentration of mercury as low as 5 × 10-9 mol l-1 (1 ppb) was detected. Satisfactory recovery was obtained when the system was tested on drinking water samples.
Arduini, F., Majorani, C., Amine, A., MOSCONE DINIA, D., Palleschi, G. (2011). Hg2+ detection by measuring thiol groups with a highly sensitive screen-printed electrode modified with a nanostructured carbon black film. ELECTROCHIMICA ACTA, 56(11), 4209-4215 [10.1016/j.electacta.2011.01.094].
Hg2+ detection by measuring thiol groups with a highly sensitive screen-printed electrode modified with a nanostructured carbon black film
ARDUINI, FABIANA;MOSCONE DINIA, DANILA;PALLESCHI, GIUSEPPE
2011-01-01
Abstract
A sensor based on a screen-printed electrode (SPE) modified with a stable dispersion of commercially available carbon black (CB) N220 was optimised and challenged with several thiol-containing compounds. This probe showed a significantly enhanced electrochemical activity respect to a bare SPE when tested with thiocholine, cysteine, glutathione and cysteamine. When challenged in amperometric batch mode, the response was stable and showed a linear dependence up to 1 × 10-5 mol l-1 for thiocholine and cysteine. The very high sensitivity towards these thiols (299 mA mol -1 l cm-2 for thiocholine and 441 mA mol-1 l cm-2 for cysteine) was then used as the basis for developing an analytical method for mercury ion detection since a non electroactive complex (thiol-Hg) is formed in the presence of the metal. By selecting an appropriate concentration of thiocholine, a concentration of mercury as low as 5 × 10-9 mol l-1 (1 ppb) was detected. Satisfactory recovery was obtained when the system was tested on drinking water samples.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
