Selective Electrochemical Epinephrine Sensor Using Self‐Assembled Monomolecular Film of 1,8,15,22‐Tetraaminophthalocyanatonickel(II) on Gold Electrode

Abstract

This article describes the highly sensitive and selective determination of epinephrine (EP) using self-assembled monomolecular film (SAMF) of 1,8,15,22-tetraamino-phthalocyanatonickel(II) (4a-Ni II TAPc) on Au electrode. The 4a-Ni II TAPc SAMF modified electrode was prepared by spontaneous adsorption of 4a-Ni II TAPc from dimethylformamide solution. The modified electrode oxidizes EP at less over potential with enhanced current response in contrast to the bare Au electrode. The standard heterogeneous rate constant (k8) for the oxidation of EP at 4a-Ni II TAPc SAMF modified electrode was found to be 1.94 Â 10 À2 cm s À1 which was much higher than that at the bare Au electrode. Further, it was found that 4a-Ni II TAPc SAMF modified electrode separates the voltammetric signals of ascorbic acid (AA) and EP with a peak separation of 250 mV. Using amperometric method the lowest detection limit of 50 nM of EP was achieved at SAMF modified electrode. Simultaneous amperometric determination of AA and EP was also achieved at the SAMF modified electrode. Common physiological interferents such as uric acid, glucose, urea and NaCl do not interfere within the potential window of EP oxidation. The present 4a-Ni II TAPc SAMF modified electrode was also successfully applied to determine the concentration of EP in commercially available injection.

Simultaneous determination of epinephrine and uric acid at a gold electrode modified by a 2-(2,3-dihydroxy phenyl)-1, 3-dithiane self-assembled monolayer

“…The electrochemical determination of EP using bare electrodes suffers from interference by UA because the oxidation potential of UA at 0.444 V is fairly close to 0.350 V for EP [31,32]. The use of chemically-modified electrodes greatly increases the selectivity and sensitivity toward these analytes.…”

“…EP and UA are coexistent in biological fluids of human, so the simultaneous detection of EP and UA in a mixture is quite attractive to biological and chemical researches. The major challenge in EP analysis is the elimination of interferences from ascorbic acid and UA; UA oxidation peak (444 mV vs. Ag/AgCl at pH 7.0) [31] is very close to that of EP (350 mV vs. Ag/AgCl at pH 7.0) [32] which often results in peak overlapping. Therefore, a lot of chemically-modified electrodes have been developed to eliminate the interference of UA to EP determination or separate the electrochemical response of EP and UA [33][34][35].…”

Synthesis of substituted phthalocyanines

“…185 Based on the surface coverage and intensity of the in-plane stretching bands from Raman studies, it has been suggested that the cobalt(II) 1,8(11),15(18),22(25)-tetraaminophthalocyanine adopts a nearly parallel orientation on the gold surface, while its 2,9(10), 16(17),23 (24)-isomer adopts the perpendicular orientation. 186 Besides adsorption, electropolymerization of transition-metal tetraaminophthalocyanines can be used for preparation of modified glassy carbon electrodes.…”

A Review on the Effects of Introducing CNTs in the Modification Process of Electrochemical Sensors

“…It is mainly used in emergency treatments in the cases such as severe allergies, cardiac arrest and asthma [57][58][59]. It is mainly used in emergency treatments in the cases such as severe allergies, cardiac arrest and asthma [57][58][59].…”