Free Base Porphyrins as Ionophores for Heavy Metal Sensors

Abstract

Two functionalized porphyrins: 5,10,15,20-tetrakis(3,4-dimethoxyphenyl) porphyrin (A) and 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (B) obtained and characterized by us were used as ionophores (I) for preparing PVC-based membrane sensors selective to Ag+, Pb2+ and Cu2+. The membranes were prepared using three different plasticizers: (bis(2-ethylhexyl)sebacate (DOS), dioctylphtalate (DOP), o-nitro-phenyl octyl ether (NPOE) and potassium tetrakis(4-chlorophenyl)borate (KTClPB) as additive. The functional parameters (linear concentration range, slope and selectivity) of the sensors with membrane composition: (I:PVC:KTClPB:Plasticizer) in different ratios were investigated. The best results were obtained for the membranes in the ratio I:PVC:KTClPB:Plasticizer 10:165:5:330. The influence of pH on the sensors response was studied. The sensors were used for a period of four months and their utility has been tested on synthetic and real samples.

Synthesis, Spectroscopic, and Biological Studies on New Zirconium(IV) Porphyrins with Axial Ligand

“…Synthesis and functionalization of porphyrins [1] have long been of great interest in the chemistry community because of the vast potentials and demands for porphyrin derivatives in diverse fields, such as materials [2, 3], supramolecular chemistry [4, 5], biomimetic models [6], catalysis [7, 8], photodynamic therapy [9], and ionophores [10]. Porphyrins were reported to exhibit a variety of biological activities.…”

Potentiometric detection and removal of copper using porphyrins

“…Due to the fact that free porphyrins have donor atoms in their structure, the expectations are to have good affinity to transition metals ions. This was proved by several papers reported in the literature [13,27,28] that mention different porphyrins as sensing material. Besides the critical role of the ionophore, the nature of the plasticizers having different dielectric constants influence the mobility of the ionophore in the membrane phase.…”

Sensors for Corrosion Detection: Measurement of Copper Ions in 3.5% Sodium Chloride Using Screen-Printed Platinum Electrodes

“…These can be very simple to fabricate (e.g. by coating a platinum wire with the ion sensitive medium), yet still demonstrate good sensitivity, high selectivity and fast response [2]- [4]. The work reported by Firooz et al is a good illustration of this type of sensor [2].…”