Porphyrin-Modified Electrodes as Biomimetic Sensors for the Determination of Organohalide Pollutants in Aqueous Samples

Abstract

A preliminary examination of a simple and rapid screening method for quantifying a range of toxic organohalides directly in aqueous solution based on their electrocatalytic reduction with a metalloporphyrin catalyst is described. Homogenous catalysis is described as well as heterogeneous catalysis using precipitated cobalt(II) tetraphenylporphine ((TPP)Co) at a graphite foil electrode which permitted the sensitive detection of a wide range of different organohalides, including a number of chemically diverse industrial pollutants such as 1,2,3,4,5,6-hexachlorocyclohexane (lindane) and carbon tetrachloride, representative of haloalkane compounds, haloalkenes such as perchloroethylene, and aromatics, such as 2,4-dichlorophenoxyacetic acid, pentachlorophenol, and the insecticide DDT. The coordinating effect of solvent on the thermodynamics of the Co(II)/(I) electrode reaction is used to practical advantage to build an amperometric detector that is insensitive to interference from oxygen, a parameter that varies considerably in environmental samples. Devices also appear relatively insensitive to the ionic composition of the analyte sample. The work provides the basis for developing a prototype sensor for screening toxic organohalogen pollutants for use in environmental monitoring situations.

Enhanced Charge Collection in MOF‐525–PEDOT Nanotube Composites Enable Highly Sensitive Biosensing

“…The electrochemical properties of MOFs have recently received significant attention in the chemical literatures 14. MOFs constructed with porphyrin subunits are particularly interesting because of their redox activity and have been tested as electrodes to detect organohalide pollutants,15 oxygen,16 and thrombin 17. The MOF architecture is important because these porphyrin‐based materials such as MOF‐525 have high specific surface areas, and the electrochemical activity of the porphyrin subunit can be tuned for different electrochemical sensing applications 18.…”

A poly(pyrrole-Cobalt(II)deuteroporphyrin) electrode for the potentiometric determination of nitrite

“…Beside immobilized iron and manganese porphyrins, cobalt complexes were also been investigated due to their promising functions as catalysts or selective complexing centers via axial ligation reactions. The latter were, for instance, successfully exploited for the study of phenol interaction [13], oxygen or NO reduction [14,15] and the detection of organohalide pollutants or nitrite [16][17][18].…”

Electrocatalysis of the reduction of organic halide derivatives at modified electrodes coated by cobalt and iron macrocyclic complex-based films: application to the electrochemical determination of pollutants

“…By immobilizing such complexes on the electrode surface, one may take profit from their electrocatalytic capabilities to conceive new analytical tools for the detection of organic halides in solution. Examples describing the use of modified electrodes based on porphyrin and Schiff base complexes, which have been immobilized by different physical ways (adsorption, chemical condensation or incorporation in an organic glue, electropolymerization) has been reported only recently [10][11][12][13][14][15].…”

“…The flow injection analysis of 2,4-dichlorophenoxy acetic acid and 2,2-dichloroacetic acid showed that the response of the modified electrode was enhanced 50 times compared to the bare electrode. More recently, Dobson and Saini [11] reported the detection of different organohalides, including a number of industrial pollutants, by using a modified electrode consisting in a graphite foil covered with adsorbed cobalt porphyrin. The authors provided significant results on the detection of three classes of halides by amperometric measurements.…”