Improvement of alternariol monomethyl ether detection at gold electrodes modified with a dodecanethiol self-assembled monolayer

Electro-oxidation of altertoxin I (ATX-I) at gold electrodes modified by dodecanethiol self-assembled monolayers

“…We also observed a slight shift ($0.023 V) of the thiol reduction peak towards more negative potentials as t mod was further increased. This behaviour would be consistent with a monolayer rearrangement, leading to a higher barrier against ion permeation [26].…”

“…The amount of adsorbed DDT was derived from the charge under the reductive desorption voltammograms recorded in 0.5 mol dm À3 KOH aqueous solutions for t mod values ranging from 2 min to 24 h. These results indicated that the electrode becomes fully covered with a thiol monolayer for modification times P5 min [26]. We also observed a slight shift ($0.023 V) of the thiol reduction peak towards more negative potentials as t mod was further increased.…”

“…The working electrode was a polycrystalline gold disk of 1.6 mm diameter obtained from BAS. It was pre-treated as previously described [26]. DDT SAMs were prepared by immersing the pre-treated gold electrode in a stirred 1 · 10 À2 mol dm À3 DDT ethanolic solution during a modification time (t mod ), which was varied from 5 s to 16 h. After modification, the electrode was washed with ethanol and then with pure water to eliminate physically adsorbed thiol molecules.…”

“…Particularly, SAMs of organosulfur compounds on gold have been widely studied because they offer several advantages, such as the combination of a high structural order, the possibility of changing the tail group as well as their easy preparation [1]. In the electrochemical field, the interest in SAM, based thiols and related molecules is due to the following aspects: (a) they can be used as insulating barriers between an electrode and a redox couple for studying long range electron transfer [7][8][9][10][11][12][13][14][15][16][17][18] and (b) they can be employed to prepare microarray electrodes which have potential applications to obtain selective voltammetric detectors or to measure very fast electron-transfer kinetics [19][20][21][22][23][24][25][26][27].…”

Development of an Electroanalytical Method for the Quantification of Zearalenone (ZEA) in Maize Samples

“…Electrochemical data for alternariol (AOH), alternariol mono-methyl ether (AME) and altertoxin I (ATX-I), produced by Alternaria [10 -12], were obtained in different reaction media by using cyclic (CV), differential pulse (DPV) and square-wave (SWV) voltammetries [13,14]. Besides, important improvements in electrochemical signal and also in detection limit are obtained when the discharge of AME is performed on self-assembled monolayers of dodecanethiol on gold electrodes [15]. Through studies performed on graphitic carbon based bioelectrodes, it has been shown that AME and AOH are substrates of the tirosynase enzyme [16].…”