A single use graphite screen -printed electrode (GSPE) was easily modified, to take advantage of the proven affinity of the nontoxic post -transition metal bismuth (Bi), for metal ions to be detected by Square Wave Anodic Stripping Voltammetry (SWASV). A bismuth oxide (Bi 2 O 3 ) or a chitosan coated (CS@Bi 2 O 3 ) nanopowder suspension was drop-casted on the graphite working electrode (WE) surface, giving rise to the precursor of a Bimodified GSPE. After that, an electrochemical reduction was performed to obtain the Bi- or the CS@Bi-GSPE. X-ray photoelectron spectroscopy and micro -X-ray fluorescence investigations were performed on the graphitic structure pre and post modification. The bismuth oxide deposition amount was considered as critical parameter to sensor performance, indicating a minimum and maximum threshold. Under improved measurement conditions, with a 300 s pre -concentration time, the attained sensors exhibited a linearity in the range (2.0-20.0) mu g L -1 in the simultaneous analysis of Pb(II) and Cd(II). The Bi-GSPE showed LODs of 1.7 and 0.5 mu g L -1 for Cd (II) and Pb(II) respectively, while 1.5 mu g L -1 for Cd(II) and 0.2 mu g L -1 for Pb(II) were recorded by the CS@Bi-GSPE. As an applicative proof in real sample, a spike test was carried out in a ground water sample, without any preliminary sample treatment.
Spectroscopic investigations of a commercial graphite screen printed electrode modified by bismuth oxide drop deposition and electrochemical reduction, for cadmium and lead ions simultaneous determination
De Benedetto A.;Rachele Guascito M.;Di Corato R.;Rinaldi R.;
2024-01-01
Abstract
A single use graphite screen -printed electrode (GSPE) was easily modified, to take advantage of the proven affinity of the nontoxic post -transition metal bismuth (Bi), for metal ions to be detected by Square Wave Anodic Stripping Voltammetry (SWASV). A bismuth oxide (Bi 2 O 3 ) or a chitosan coated (CS@Bi 2 O 3 ) nanopowder suspension was drop-casted on the graphite working electrode (WE) surface, giving rise to the precursor of a Bimodified GSPE. After that, an electrochemical reduction was performed to obtain the Bi- or the CS@Bi-GSPE. X-ray photoelectron spectroscopy and micro -X-ray fluorescence investigations were performed on the graphitic structure pre and post modification. The bismuth oxide deposition amount was considered as critical parameter to sensor performance, indicating a minimum and maximum threshold. Under improved measurement conditions, with a 300 s pre -concentration time, the attained sensors exhibited a linearity in the range (2.0-20.0) mu g L -1 in the simultaneous analysis of Pb(II) and Cd(II). The Bi-GSPE showed LODs of 1.7 and 0.5 mu g L -1 for Cd (II) and Pb(II) respectively, while 1.5 mu g L -1 for Cd(II) and 0.2 mu g L -1 for Pb(II) were recorded by the CS@Bi-GSPE. As an applicative proof in real sample, a spike test was carried out in a ground water sample, without any preliminary sample treatment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.