Fabrication of Lead Ion Selective Electrodes (Pb-ISE) based on Poly Methyl-Methacrylate-Co-Butyl Acrylate (MB28) Thin Film Photo-polymers and Pencil Graphite Electrodes (PGEs)

Abstract

The purpose of this study was to fabricate lead ion selective electrode (Pb-ISE) sensors based on a 2:8 ratio of methyl-methacrylate-co-butyl acrylate thin film copolymers (MB28). These sensors were prepared by using a photo-polymerization technique on a pencil graphite electrode (PGE), with a poly-pyrrole-Cl (p-Py-Cl) thin film as a sensor transducer. During the Pb-ISE sensor fabrication process, the membrane composition optimization process has been carried out. The best sensor composition contained 1 mg potassium tetrakis (4-chlorophenyl) borate (KTpClPB) and 4.3 mg Pb ionophore IV. The fabricated Pb-ISE had a Nernstian number of 28.2 ± 0.5 mV/dec, a broad linear range from 10 -3 to 10 -10 M and a limit of detection (LOD) of (6.6 ± 1.6) x 10 -11 M, providing an excellent performance. In addition, the sensor showed a fairly good coefficient of effectiveness (CE) (Log K pota,b ) against K + (potassium), Na + (sodium), NH 4+ (ammonium), Mg 2+ (magnesium), Cu 2+ (copper) and Cd 2+ (cadmium) cations, which were -6.6 ± 0.2, -6.1 ± 0.2, -6.7 ± 0.2, -12.4 ± 0.3, -4.4 ± 0.2 and -6.1 ± 0.1, respectively. The Pb-ISE sensor worked best in the pH range from 3 to 8. The validation process has been carried out by comparing the measurements results of the artificial samples, at the concentrations from 25 to 100 ppm, with those of the real sample from Angke river water. The outcome was outstanding and comparable to that of the standard UV-Vis spectrophotometry measurement methods.